Novel benzaldehydes

Abstract

Novel benzonitriles, benzaldehydes and benzyl alcohols of the formula I ##STR1## where R.sup.1 is methyl or ethyl, R.sup.2 is alkyl, alkenyl, cycloalkyl, cycloalkenyl, bicycloalkyl, bicycloalkenyl, or C.sub.1 -C.sub.5 -alkyl-substituted cycloalkyl, cycloalkenyl, bicycloalkyl or bicycloalkenyl, X is hydrogen, chlorine or fluorine and Z is --CN, CHO or ##STR2## where R.sup.3 is hydrogen, cyano, C.sub.2 -C.sub.4 -alkynyl, C.sub.2 -C.sub.4 -alkenyl or C.sub.1 -C.sub.4 -alkyl, with the proviso that R.sup.2 is not --CH.sub.2 --CH.dbd.CH--B when B is hydrogen, alkyl or alkenyl and at the same time R.sup.1 is methyl and Z is ##STR3## and with the proviso that R.sup.2 is not methyl or ethyl when R.sup.1 is methyl and at the same time Z is ##STR4## and furthermore with the proviso that R.sup.2 is not methyl when R.sup.1 is methyl or ethyl and at the same time Z is --CN or --CHO.

Description

The present invention relates to novel benzonitriles, benzaldehydes and benzyl alcohols of the general formula I ##STR5## where R.sup.1 is methyl or ethyl, R.sup.2 is alkyl, alkenyl, cycloalkyl, cycloalkenyl, bicycloalkyl, bicycloalkenyl or C.sub.1 -C.sub.5 -alkyl-substituted cycloalkyl, cycloalkenyl, bicycloalkyl or bicycloalkenyl, X is hydrogen, chlorine or fluorine and Z is --CN, CHO or ##STR6## where R.sup.3 is hydrogen, cyano, C.sub.2 -C.sub.4 -alkynyl, C.sub.2 -C.sub.4 -alkenyl or C.sub.1 -C.sub.4 -alkyl, with the proviso that R.sup.2 is not --CH.sub.2 -CH.dbd.CH--B when B is hydrogen, alkyl or alkenyl and at the same time R.sup.1 is methyl and Z is ##STR7## and with the proviso that R.sup.2 is not methyl or ethyl when R.sup.1 is methyl and at the same time Z is ##STR8## and furthermore with the proviso that R.sup.2 is not methyl when R.sup.1 is methyl or ethyl and at the same time Z is --CN or --CHO.

2,3-Dimethylbenzyl alcohol, 3-ethyl-2-methylbenzyl alcohol and 2,3-dimethyl-.alpha.-methylbenzyl alcohol are described in, for example, J. Chem. Soc., Perkin Trans. 1 (12) (1981), 3087-3091; J. Chem. Soc., Perkin Trans. 1 (20) (1974), 2339-2342; Helv. Chim. Acta, 60 (5) 1758-1780 and Tetrahedron Lett. 22 (1981), 161-162.

Furthermore, Pestic. Sci. 17 (6) (1986), 691-700 discloses certain ortho-methylbenzyl alcohols which carry in the meta-position an allyl radical which may be substituted at the terminal position.

2,3-Dimethylbenzaldehyde and 2-ethyl-3-methylbenzaldehyde are described in J. Chem. Soc., Perkin Trans. 1 (1981), 3087-3091, J. Org. Chem. 47 (1982), 1361-1364 and Indian J. Chem. Sect. B, 258 (1986), 1112-1117.

2,3-Dimethylbenzonitrile, 2-ethyl-3-methylbenzonitrile and 4-chloro-2,3-dimethylbenzonitrile are disclosed in J. Chem. Soc., Perkin Trans. 2 (1983), 1003-1010, Indian J. Chem. Sect. B, 25B (1986), 1112-1117 and J. Chem. Soc., 1964, 2258-2261.

It is an object of the present invention to provide novel intermediates for the preparation of pesticides, in particular of benzyl esters of the structure IV ##STR9## where A is a carboxylate radical of an acid component typical for pyrethroids and R.sup.1 to R.sup.3 and X have the abovementioned meanings.

We have found that this object is achieved and that the compounds defined at the outset are particularly suitable for the preparation of benzyl esters IV which have good insecticidal and acaricidal activity and are described in contemporaneous German Application P No. 38 20 896.2.

The benzyl esters of the formula IV can be obtained by reacting an acid A-H, some typical examples of which are listed below, or a derivative of this acid, such as an acyl chloride, an anhydride or the like, with a benzyl alcohol of the general formula Ia or a derivative thereof in accordance with the equation below. ##STR10## R.sup.1 to R.sup.3 and X have the abovementioned meanings.

Typical examples of the acids of the formula A-H are:

A.sup.1 -H: 3-(2',2'-dimethylvinyl)-2,2-dimethylcyclopropane-2-carboxylic acid A.sup.2 -H: 3-(2',2'-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid A.sup.3 -H: 3-(2'-chloro-3',3',3'-trifluoroprop-1-enyl)-2,2-dimethylcyclopropane-1-carboxylic acid A.sup.4 -H: 3-(2',2'-dibromovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid A.sup.5 -H: 3-(2',2'-difluorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid A.sup.6 -H: 3-(2'-fluoro-3',3',3'-trifluoroprop-1'-enyl}-2,2-dimethylcyclopropane-1-carboxylic acid A.sup.7 -H: 3-(2',2'-bistrifluoromethylvinyl)-2,2-dimethyl-cyclopropane-1-carboxylic acid A.sup.8 -H: 2-(4'-chlorophenyl)-3-methylbutyric acid A.sup.9 -H: 2-(4'-fluorophenyl)-3-methylbutyric acid A.sup.10 -H: 2-(4'-difluoromethoxyphenyl)-3-methylbutyric acid A.sup.11 -H: 3-(4'-tert-butylphenyl)-2,2-dimethylcyclopropane-1-carboxylic acid A.sup.12 -H: 2,2,3,3-tetramethylcyclopropane-1-carboxylic acid A.sup.13 -H: 1-(4'-chlorophenyl)-cyclopropane-1-carboxylic acid A.sup.14 -H: 1-(4'-ethoxyphenyl)-2,2-dichlorocyclopropane-1-carboxylic acid A.sup.15 -H: 3-[2'-(4H.sub.2 -chlorophenyl)-2'-chlorovinyl]-2,2-dimethylcyclopropane-1-carboxylic acid A.sup.16 -H: 3-(1',3'-butadienyl)-2,2-dimethylcyclopropane-1-carboxylic acid A.sup.17 -H: 3-(2'-methyl-2,-methoxycarbonylvinyl)-2,2-dimethylcyclopropane-1-carboxylic acid A.sup.18 -H: 2-(2'-chloro-4'-trifluoromethylphenylamino)-3-methylbutyric acid A.sup.19 -H: 2-(2'-fluoro-4'-trifluoromethylphenylamino)-3-methylbutyric acid A.sup.20 -H: 3-methyl-2-(4'-trifluoromethylphenylamino)-butyric acid A.sup.21 -H: 2-methyl-2-(pyrrol-1'-yl)-butyric acid A.sup.22 -H: 3-methyl-2-(3,-methylpyrrol-1'-yl)-butyric acid A.sup.23 -H: 2-(3',4'-dimethylpyrrol-1'-yl)-methylbutyric acid A.sup.24 -H: 2-(2',5'-dimethylpyrrol-1'-yl)-methylbutyric acid A.sup.25 -H: 2-(isoindoline-2-yl)-3-methylbutyric acid A.sup.26 -H: 1,1-dimethyl-2,2[H]indenespirocyclopropane-3-carboxylic acid A.sup.27 -H: 3-cyclopentylidenemethyl-2,2-dimethyl-cyclopropane-1-carboxylic acid A.sup.28 -H: 3-(1',2'-dibromo-2',2'-dichloroethyl)-2,2-dimethylcyclopropane-1-carboxylic acid A.sup.29 -H: 3-methyl-2-(pyrazol-1'-yl)-butyric acid A.sup.30 -H: 3-methyl-2-(imidazol-1'-yl)-butyric acid

The reaction can be accelerated in a conventional manner by adding a catalyst, such as sulfuric acid, a hydrogen halide, a sulfonic acid or an acidic ion exchanger and the equilibrium of the esterification can be shifted in the desired direction by removing the water or the ester IV from the reaction mixture, for example by azeotropic distillation or by binding the water to sulfuric acid or a hydrohalic acid.

The corresponding acyl chlorides can also be reacted with the alcohols of the formula Ia in the presence of an acid acceptor (cf. Houben-Weyl, Methoden der organischen Chemie, Volume VIII, page 541 et seq., Georg-Thieme-Verlag, Stuttgart 1952).

Suitable acid acceptors are the conventional basic agents, in particular aliphatic, aromatic and heterocyclic amines, eg. triethylamine, dimethylamine, piperidine, dimethylaniline, dimethylbenzylamine, pyridine and 2-picoline.

The reaction can be carried out in a solvent or diluent. The stated acid acceptors themselves or, for example, the following solvents or diluents or mixtures thereof are suitable for this purpose:

Aliphatic and aromatic hydrocarbons and chlorohydrocarbons, such as petroluem ether, benzene, toluene, xylene, gasoline, dichloromethane, chloroform, tetrachloromethane, 1,2-dichloroethane or chlorobenzene; ethers, such as diethyl and di-n-butyl ether, methyl tert-butyl ether, tetrahydrofuran and dioxane; ketones, for example acetone, methyl ethyl ketone and methyl isopropyl ketone; and nitriles, such as acetonitrile and propionitrile.

The starting materials are usually produced in a stoichiometric ratio. However, an excess of one or other of the starting materials may be quite advantageous in specific cases.

The reaction usually takes place at a sufficient rate at above 0.degree. C. Since it is generally exothermic, it may be advantageous to provide a means of cooling.

In some cases, it is useful and advantageous to esterify the compounds of the formula Ia in situ, particularly when R.sup.4 in the general formula Ia is a cyano group.

The novel esters may furthermore be prepared by virtually any known method of ester synthesis, for example by reacting the corresponding anhydride with an alcohol of the formula Ia, reacting the corresponding salt with a derivative of an alcohol of the formula Ia or by transesterification (cf. Houben-Weyl, loc. cit., pages 508-628).

In the present invention, the terms have the following meanings, unless stated otherwise:

Alkyl is straight-chain or branched alkyl of 1 to 20, in particular 1 to 12, carbon atoms. Examples are methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, secbutyl and tert-butyl.

Alkenyl is a straight-chain or branched, ethylenically unsaturated hydrocarbon group having 2 to 20, in particular 2 to 12, carbon atoms and 1 to 10, in particular 1 to 5, ethylenic bonds. Examples are vinyl, isopropenyl, 1-butenyl, 1,5-hexadienyl, 1-methylpropenyl and 1-ethylvinyl.

Cycloalkyl is a cycloalkyl group having 3 to 8, in particular 3 to 6, carbon atoms in the ring, such as cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl. This cycloalkyl group is unsubstituted or substituted by one or more, for example 1 to 4, branched or straight-chain C.sub.1 -C.sub.5 -alkyl radicals, such as methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl or pentyl. Examples are 3,5-diethylcyclohexyl and tetramethylcyclopropyl.

Cycloalkenyl is a cycloalkenyl group having 3 to 8, in particular 3 to 6, carbon atoms in the ring, such as cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclopentadienyl or cyclohexadienyl. This cycloalkenyl group is unsubstituted or substituted by one or more, for example 1 to 4, branched or straight-chain C.sub.1 -C.sub.5 -alkyl radicals, such as methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl or pentyl. Examples are 1-cyclopentenyl, 1-cyclohexenyl, 3,5-dimethyl-1-cyclohexenyl and 1,3-cyclohexadienyl.

Bicycloalkyl is a bicycloalkyl radical having 5 to 12, in particular 6 to 8, carbon atoms in the bicyclic structure, eg. 2-norbornyl or bicyclo[4.1.0]hept-1-yl. This bicyclic structure is unsubstituted or substituted by one or more, for example 1 or 2, branched or straightchain alkyl radicals, such as methyl, ethyl, propyl, isopropyl, butyl, sec-butyl or pentyl. An example is 2,6-dimethylbicyclo[4.1.0]hept-1-yl.

Bicycloalkenyl is an unsaturated bicycloalkyl group having 5 to 12, in particular 6 to 8, carbon atoms in the bicyclic structure and one or more, for example 1 or 2, ethylenic double bonds, eg. norbornen-2-yl or nor- bornadien-2-yl. This bicycloalkenyl group is unsubstituted or substituted by one or more, for example 1 to 3, branched or straight-chain C -C:-alkyl radicals, such as methyl, ethyl, propyl, isopropyl, butyl, sec-butyl or pentyl. An example is 7,7-dimethylbicyclo[4.1.0]hept-2-en-1-yl.

R.sup.3 is hydrogen, cyano, C.sub.2 -C.sub.4 -alkynyl, such as ethynyl, propyn-1-yl, propyn-2-yl or butynyl, C.sub.2 -C.sub.4 -alkenyl, such as vinyl, allyl or butenyl, or C -C -alkyl, such as methyl, ethyl, propyl, isopropyl or butyl.

In the compounds I, R.sup.1 is preferably methyl, R.sup.2 is preferably a branched alkyl or alkenyl radical of 3 to 8 carbon atoms, such as isopropyl, isopropenyl, sec-butyl, 1-buten-2-yl, 1-methyl-1-propenyl, 1,3-butadienyl, isopentyl, sec-pentyl, 3-penten-3-yl, 1-penten-2-yl or sec-hexyl, the three first-mentioned radicals being particularly preferred, C.sub.3 -C.sub.8 -cycloalkyl or cycloalkenyl, such as cyclopentyl, 1-cyclopentenyl, cyclohexyl, 1-cyclohexenyl or cyclopropenyl, or C.sub.6 -C.sub.8 -bicycloalkyl or bicycloalkenyl, such as 2-norbornyl, 2-norbornen-2-yl or 2,5-norbornadien-2-yl, R.sup.3 is hydrogen, ethynyl or cyano and X is hydrogen or fluorine.

The novel compounds are prepared by the following processes:

Benzyl alcohols of the general formula Ia ##STR11## are obtained starting from a correspondingly substituted benzaldehyde of the formula Ib ##STR12## by reacting it with: (i) a reducing agent if R.sup.3 is H,

(ii) hydrocyanic acid or a metal cyanide in the presence or absence of an acid if R.sup.3 is CN or (iii) a metalorganyl MeR.sup.3 or R.sup.3 MeHal if R.sup.3 is C.sub.2 -C.sub.4 -alkynyl, C.sub.2 -C.sub.4 -alkenyl or C.sub.1 -C.sub.4 -alkyl, Me being an alkali metal, alkaline earth metal or transition metal and Hal being halogen.

Suitable reducing agents are all conventional reducing agents which convert benzaldehydes into benzyl 1 alcohols (Houben-Weyl, Methoden der organischem Chemie, Volume VI/lb, pages 1-500, 1984 Edition, Georg Thieme Verlag, Stuttgart). In addition to the catalytic hydrogenation, nonmetallic reducing agents and metal hydrides, in particular complex metal hydrides, eg. lithium aluminum hydride or sodium borohydride are suitable. Cathodic and photochemical reduction are also suitable.

For the preparation of the cyanohydrins, the benzaldehydes are reacted with hydrocyanic acid, with hydrocyanic acid produced in situ from metal cyanides, or with metal cyanides in the presence of an alkali metal bisulfite solution, if necessary basic catalysts, such as potassium carbonate, or phase transfer catalysts, eg. benzyltriethylammonium chloride, being added.

Preferably used metal cyanides are alkali metal cyanides, eg. sodium cyanide or potassium cyanide.

The reaction is carried out in a conventional manner, for example as described in Houben-Weyl, Methoden der organischen Chemie, Volume VIII, pages 274-278, 1952 Edition, and Volume E5, page 1413 et seq., 1985 Edition.

Suitable metalorganyls are the corresponding organometallic compounds, in particular lithiumorganyl compounds LiR.sup.3, such as methyllithium, ethyllithium or butyllithium or the corresponding Grignard compounds R.sup.3 MgHal, where Hal is chlorine, bromine or iodine, eg. methylmagnesium bromide, ethylmagnesium chloride, propylmagnesium iodide or vinylmagnesium iodide.

The reaction of the metalorganyls can be carried out in a conventional manner, for example as described in Houben-Weyl, Methoden der organischen Chemie, Volume 2a, page 285 et seq., 1973, in an inert organic solvent such as ether or tetrahydrofuran, under a protective gas, so that no further information is required in this context

The benzaldehydes Ib are prepared by reacting a correspondingly substituted benzonitrile Ic ##STR13## with a reducing agent to give an aldimine II ##STR14## and hydrolyzing this in a conventional manner.

This reaction sequence is shown in the following equation: ##STR15##

In addition to hydrogen (catalytic hydrogenation) and tetrachlorostannous acid, particularly suitable reducing agents are aluminum hydrides, eg. diisopropylaluminum hydride (cf. Houben-Weyl, Methoden der organischen Chemie, Volume E3, pages 476-488, Georg Thieme Verlag, Stuttgart). The hydrolysis of the aldimines II is carried out as a rule by treatment with a dilute or concentrated mineral acid, such as hydrochloric acid. In the case of sensitive aldehydes, it is advisable to use buffered acetic acid.

It is not absolutely essential to isolate the aldimines II. They can advantageously be hydrolyzed immediately to the benzaldehydes Ib, without working up and purification.

The benzonitriles of the general formula Ic are prepared by reacting ##STR16## compounds of the general formula III ##STR17## where Y is chlorine or bromine, with metal cyanides in an organic solvent in accordance with the following equation. ##STR18##

Suitable metal cyanides (MeCN) are alkali metal, alkaline earth metal and heavy metal cyanides (Houben-Weyl, Methoden der organischen Chemie, Volume E5, pages 1447-1467, 1985 Edition, Georg Thieme Verlag, Stuttgart). The use of copper(I) cyanide is particularly advantageous. The reaction takes place smoothly in aprotic, polar solvents. Dimethylformamide, pyridine, 1-methyl-2-pyrrolidone and phosphoric acid tris-(dimethylamide) are particularly suitable.

The reaction is advantageously carried out at from 100 to 250.degree. C. When copper(I) cyanide is used, the reaction mixture is worked up (destruction of the initially formed nitrile/copper halide/copper cyanide complex) with iron(III) chloride/hydrochloric acid, 1,2-diaminoethane or sodium cyanide. 1,2-Diaminoethane is advantageously used.

Specific examples of the compounds III, such as 2-chloro-6-n-butyltoluene, 3-chloro-2-methylstyrene, 1-chloro-2-methyl-3-(1'-propenyl)-benzene, 2,3-dimethylchlorobenzene, 2,3-dimethylbromobenzene, 4-fluoro-2,3-dimethylbromobenzene, 1,2-dichloro-3,4-dimethylbenzene, 1,5-dichloro-2,3-dimethylbenzene and 1,4-dichloro-2,3-dimethylbenzene are disclosed in U.S. Pat. No. 4,538,003; European Patent No. 80 359; J. Med. Chem. 28 (10), 1436-1440; J. Chromatogr. 370 (3) (1986), 355-376; Gazz. Chim. Hal., 103 (8-9) (1973), 1019-1025 or Chem.-Ztg. 103 (1) (1979), 1-7.

A general synthesis route for the preparation of the compounds of the formula III where R.sup.1, R.sup.2, X and Y have the abovementioned meanings starts from dichloro-, dibromo-, dibromochloro-, dibromofluoro- or dichlorofluorobenzene derivatives Va and is illustrated by the following reaction scheme: ##STR19##

In this reaction scheme, the side chains ##STR20## correspond to the radical R.sup.2. R.sup.4, R.sup.5 and R.sup.6 are each hydrogen, branched or straight-chain alkyl or branched or straight-chain alkenyl. R.sup.4 and R.sup.6 or R.sup.5 and R.sup.6 may furthermore be bonded to form a ring, which may be substituted by C.sub.1 -C.sub.5 -alkyl, or R.sup.4, R.sup.5 and R.sup.6 are such that they form a bicyclic ketone, which may be substituted by C.sub.1 -C.sub.5 -alkyl.

Di- or trihalobenzenes of the general formula Va, where R.sup.1 is methyl or ethyl, X is hydrogen, chlorine or fluorine and Y is chlorine or bromine, are converted into the monometalorganyls of the general formula Vb (organolithium compound or Grignard compound), where X, Y and R.sup.1 have the meaning stated for Va and M is lithium or MgY.

The conventional preparation processes which start from aryl halides (cf. Houben-Weyl, Methoden der organischen Chemie, Volume XIII/1, page 134 et seq., 1970 Edition, and Volume XIII/2a, page 54 et seq., 1973 Edition, Georg Thieme Verlag, Stuttgart) are suitable for the preparation of organolithium or Grignard compounds. Where Y is chlorine and X is hydrogen, the synthesis of the Grignard compounds requires higher reaction temperatures. The use of tetrahydrofuran at boiling point has proven particularly useful.

The organometallic compounds Vb are reacted with carbonyl compounds VI, in which R.sup.4 to R.sup.6 have the abovementioned meanings, to give benzyl alcohols VII. These are dehydrated to styrenes of the general formula III', the methods described in Houben-Weyl (Methoden der organischen Chemie, Volume V/Ib, page 45 et seq., 1972 Edition, Georg-Thieme-Verlag, Stuttgart) being suitable. It is advantageous to use acidic dehydrating agents, in particular oxalic acid or p-toluenesulfonic acid, with simultaneous removal of the resulting water by means of a separator.

The styrene derivatives III, prepared in the manner described above are either used directly for the preparation of the benzonitriles of the general formula Ic or first converted into compounds of the general formula III", by reduction. This may be effected both by noncatalytic reduction (for example with ethanol and sodium) and by catalytic hydrogenation (cf. Houben-Weyl, Methoden der organischen Chemie, Volume V/la, page 405 et seq., 1970 Edition, Georg Thieme Verlag, Stuttgart). Examples of suitable catalysts are PtO.sub.2, Raney nickel, Pd/carbon, Pd/CaCO.sub.3, copper chromite or Pd/Al.sub.2 O.sub.3. The use of Pd/carbon has proven particularly useful. Suitable solvents are alcohols, eg. methanol, ethanol or isopropanol, ethers, eg. tetrahydrofuran or dioxane, and esters, eg. ethyl acetate. It is advantageous to use ethanol. The catalytic hydrogenation is carried out, as a rule, at room temperature and under from 1 to 150 bar. Small amounts of compounds in which halogen/hydrogen exchange has additionally taken place are often formed as byproducts.

Compounds of the general formula III ##STR21## where R.sup.2 is a tertiary alkyl radical or tertiary alkenyl radical, can be prepared starting from compounds of the general formula Va.

The following reaction scheme is intended as an example of the synthesis route: ##STR22##

Compounds of the general formula I ##STR23## where R.sup.2 is unsubstituted or substituted cyclopropyl, can be obtained by various methods:

(a) the process described in claims 3-5, in which the required starting materials XV can be obtained by an addition reaction of a dihalocarbene with compounds of the general formula III' followed by dehalogenation (for example with tri-n-butyltin hydride). ##STR24## (R.sup.4, R.sup.5 and R.sup.6 are each H or C.sub.1 -C.sub.5 -alkyl)

(b) Dihalocarbene addition and subsequent dehalogenation are carried out in a subsequent stage (correspondingly substituted benzonitriles, benzaldehydes or benzyl alcohols), where Z, X, R.sup.1 and R.sup.4 -R.sup.5 have the abovementioned meanings: ##STR25## where Z is --CHO or ##STR26## it is advantageous to introduce protective groups for these functional groups beforehand (for example acetal or tetrahydropyranyl ether) and to eliminate these in a conventional manner after the dehalogenation.

The novel compounds or their intermediates are prepared in accordance with the descriptions of the following examples or by appropriate modification of these examples.

EXAMPLE 1

Preparation of benzyl alcohols VII

1-(3'-Chloro-2'-methylphenyl)-cyclohexanol 96 g (4 moles) of Mg turnings in 60 ml of absolute tetrahydrofuran (THF) are initially taken under a nitrogen atmosphere. 1 ml of 1,2-dibromoethane is added at 65.degree. C., after which a solution of 644 g (4 moles) of 2,6-dichlorotoluene in 1.5 1 of absolute THF is added dropwise in the course of 21/4hours. Thereafter, the mixture is stirred for 4 hours under reflux and cooled to room temperature, and 352.8 g (3.6 moles) of cyclohexanone in 250 ml of absolute THF are added under nitrogen. When the reaction is complete, the Grignard reaction mixture is worked up in an aqueous medium in a conventional manner and the solvent is substantially removed by distillation under reduced pressure. The residue is subjected to incipient distillation (30.degree.-107.degree. C./0,27 mbar). The remaining crude product (676 g), which contains as much as 90% of I-(3'-chloro-2'-methylphenyl)-cyclohexanol, can be further purified by column chromatography using toluene as the mobile phase.

300 MHz NMR spectrum in CDCl.sub.3 .delta. [ppm]=1.58-2.0(1OH); 2.65(3H); 7.04(1H); 7.23-7.34(2H)

For example, the following alcohols, which are characterized by the physical data stated, are prepared by the process described above:

______________________________________ ##STR27## mp.: 55-59.degree. C. ##STR28## 300 MHz NMR spectrum in CDCl.sub.3 : .delta. [ppm] = 0.82(3H); 1.62(3H); 1.86- 2.07[2H + 1H(OH)]; 2.59(3H); 7.06(1H); 7.29(1H); 7.36(1H) ##STR29## 300 MHz NMR spectrum in CDCl.sub.3 : .delta. [ppm] = 0.84(3H); 0.96(3H); 1.83-1.96(1H); 2.19(1H); 2.32(3H); .63(1H); 7.1(1H); 7.23-7.33(2H) ##STR30## mp.: 113.degree. C. ##STR31## mp.: 90-93.degree. C. ##STR32## mp.: 52-55.degree. C.______________________________________

EXAMPLES 2 TO 31

Preparation of halobenzene derivatives III

2-Methyl-3-isopropenylchlorobenzene

190 g of 3-chloro-2-methyl-alpha, alpha-dimethylbenzyl alcohol are refluxed with 1.5 1 of toluene and 370 g of oxalic acid under a water separator until no more water separates off. The oxalic acid is filtered off under suction and the filtrate is washed with sodium bicarbonate solution, dried over sodium sulfate and evaporated down. Fractional distillation of the residue gives 91.5 g of the desired compound, which is listed in Table 1 as Example 2. 300 MHz NMR spectrum in CDCl.sub.3 : .delta. [ppm]=1.98(3H); 2.32(3H); 4.82(1H); 5.17(1H); 6.95-7.07(2H); 7.23(1H) 3-Cyclohexyl-2-methylchlorobenzene

103 g of 1-(3'-chloro-2'-methylphenyl)-cyclohexene are dissolved in 1,200 ml of ethanol, and 5 g of Pd/carbon are added. Hydrogenation is carried out for 8 hours at room temperature and under a hydrogen pressure of 80 bar. The catalyst is filtered off from the reaction mixture and the solution is evaporated down. Fractional distillation gives 51.8 g of 3-cyclohexyl-2methylchlorobenzene (Example 3 in Table 1).

300 MHz NMR spectrum in CDCl.sub.3 : .delta. [ppm]=1.2-1.49(5H); 1.7-1.92(5H); 2.36(3H); 2.72(1H); 7.01-7.2(3H).

The compounds stated in Table 1 below were prepared similarly to Example 2 or 3 described above and are characterized by the physical data stated; the other compounds in Table 1 can readily be obtained using corresponding starting materials.

TABLE 1__________________________________________________________________________Halobenzene derivatives of the formula III ##STR33## IIIExample Y R.sup.1 R.sup.2 X Physical Data__________________________________________________________________________ 2 Cl CH.sub.3 Isopropenyl H bp. 54-55.degree. C./0.13 mbar 3 Cl CH.sub.3 Cyclohexyl H bp. 88-93.degree. C./0.013 bar 4 Cl CH.sub.3 n-Propyl H 5 Cl CH.sub.3 ##STR34## H 6 Br CH.sub.3 Cyclopentyl H 7 Cl CH.sub.3 l-Cyclohexenyl H bp. 95-98.degree. C./0.2 mbar n.sub.D.sup.23 = 1.5501 8 Br C.sub.2 H.sub.5 Isopropyl H 9 Cl CH.sub.3 Cyclohexyl 5-F10 Cl CH.sub.3 Isopropyl 5-Cl11 Cl CH.sub.3 Isopropyl H bp. 55.degree. C./0.27 mbar12 Br CH.sub.3 Isopropyl H13 Cl C.sub.2 H.sub.5 Isopropenyl H14 Br CH.sub.3 Isopropenyl H15 Cl CH.sub.3 sec-Butyl H bp. 58-60.degree. C./0.13 mbar16 Cl CH.sub.3 ##STR35## H17 Cl CH.sub.3 1-Cyclopentenyl H18 Cl CH.sub.3 2,5-Norbornadien-2-yl H bp. 113.degree. C./0.06 mbar19 Cl CH.sub.3 2-Norbornen-2-yl H n.sub.D.sup.21 = 1,570220 Cl CH.sub.3 2-Norbornen-2-yl 5-F21 Br CH.sub.3 2-Norbornen-2-yl H22 Cl C.sub.2 H.sub.5 Norborn-2-yl H23 Cl CH.sub.3 Norborn-2-yl H bp. 109-110.degree. C./0.013 mbar24 Cl CH.sub.3 3,5-Diethylcyclohexyl H25 Cl CH.sub.3 1,3-Cyclohexadienyl H26 Br CH.sub.3 ##STR36##27 Cl CH.sub.3 ##STR37## H bp. 70-72.degree. C./0.013 mbar28 Cl C.sub.2 H.sub.5 ##STR38## H29 Cl CH.sub.3 ##STR39## H30 Cl CH.sub.3 ##STR40## H31 Cl CH.sub.3 CH(C.sub.2 H.sub.5).sub.2 H bp. 60-62.degree. C./0.013 mbar__________________________________________________________________________

EXAMPLES 32 TO 65 AND 131

Preparation of benzonitriles Ic

3-(1'-cyclohexenyl)-2-methylbenzonitrile

250g (0.6 mole) of 1-(3'-chloro-2'-methylphenyl)-cyclohexene, 600 ml of 1-methyl-2-pyrrolidone and 63 g of anhydrous copper(I) cyanide are heated to the boil for 35 hours while stirring. The reaction mixture is poured into a solution of 500 ml of ethylenediamine in 1.5 1 of water and the mixture is stirred for 45 minutes at 50.degree. C. and extracted several times with toluene. The combined organic phases are extracted by shaking with 10% strength sodium cyanide solution, dried over Na.sub.2 SO.sub.4 and evaporated down. Purification by column chromatography over silica gel using 3 : 7 toluene/cyclohexane as the eluent gives 15 117.8 g of the nitrile of melting point 54-57.degree. C. 250 MHz NMR spectrum in CDCl.sub.3 : .delta. [ppm]=1.72(4H); 2.13(4H); 2.46(3H); 5.55(1H); 7.17-7.31(2H); 7.49(1H)

The novel benzonitriles stated in Table 2 were prepared by the process described above and are characterized by the physical properties stated; the other compounds in Table 2 can readily be obtained using corresponding starting materials.

TABLE 2__________________________________________________________________________Benzonitriles of the formula Ic ##STR41## IcExample R.sup.1 R.sup.2 X Physical Properties__________________________________________________________________________32 CH.sub.3 1-Cyclohexenyl H mp.: 54 to 57.degree. C.33 CH.sub.3 n-Propyl H34 CH.sub.3 n-Butyl H35 CH.sub.3 CH(C.sub.2 H.sub.5).sub.2 H n.sub.D.sup.23 : 1.511936 C.sub.2 H.sub.5 Isopropyl H37 CH.sub.3 Isopropyl H 300-MHz-NMR-spectrum in CDCl.sub.3 : .delta. [ppm] = 1.23(6H); 2.55(3H); 3.19(1H); 7.25(1H); 7.46(2H)38 CH.sub.3 Isopropyl 6-F39 CH.sub.3 ##STR42## H40 C.sub.2 H.sub.5 Isopropenyl H41 CH.sub.3 ##STR43## H42 CH.sub.3 Isopropenyl H 200-MHz-NMR-spectrum in CDCl.sub.3 : .delta. [ppm] = 2.02(3H); 2.52(3H); 4.89(1H); 5.3(1H); 7.22-7.4(2H); 7.56(1H) -43 CH.sub.3 Isopropenyl 5-Cl44 CH.sub.3 ##STR44## H45 CH.sub.3 ##STR45## H46 CH.sub.3 ##STR46## H47 CH.sub.3 sec. Butyl H 200-MHz-NMR-spectrum in CDCl.sub.3 : .delta. [ppm] = 0.84(3H); 1.2(3H); 1.61(2H); 2.54(3H); 2.94(1H); 7.2-7.31(1H); 7.43(2H)48 C.sub.2 H.sub.5 sec. Butyl H49 CH.sub.3 ##STR47## H50 C.sub.2 H.sub.5 CH(C.sub.2 H.sub.5).sub.2 H51 CH.sub.3 Cyclopentyl H52 CH.sub.3 Cyclohexyl H 300-MHz-NMR-spectrum in CDCl.sub.3 : .delta. [ppm] = 1.2-1,5(5H); 1.71-1,93(5H); 2.55(3H); 2.75(1H); 7.23(1H); 7.42(2H)53 CH.sub.3 Cyclopropyl H54 CH.sub.3 1-Cyclopentenyl H55 CH.sub.3 1,3-Cyclohexadienyl H56 CH.sub.3 2-Norbornen-2-yl H57 CH.sub.3 Norborn-2-yl H mp. 74 to 76.degree. C.58 C.sub.2 H.sub.5 Cyclohexyl H59 CH.sub.3 2,5-Norbornadien-2-yl H60 CH.sub.3 Cycloheptyl H61 CH.sub.3 ##STR48## H62 CH.sub.3 ##STR49## H n.sub.D.sup.22 : 1.525463 CH.sub.3 ##STR50## 5-F64 C.sub.2 H.sub.5 ##STR51## H65 CH.sub.3 CH(i-C.sub.3 H.sub.7).sub.2 H131 CH.sub.3 ##STR52## H 300-MHz-NMR-spectrum in CDCl.sub.3 : .delta. [ppm] = 0.65(3H); 1.41(6H); 1.83(2H); 2.72(3H); 7.2(1H); 7.5(2H)__________________________________________________________________________

EXAMPLES 66 TO 94 AND 132

Preparation of the benzaldehydes Ib

3-(1'-cyclohexenyl)-2-methylbenzaldehyde

460 ml (0.69 mole) of diisobutylaluminum hydride solution (25% strength solution in toluene) are carefully added dropwise at 20-30.degree. C. to a solution of 113 g (0.574 mole) of 3-(1'-cyclohexenyl)-2-methylbenzonitrile in 1,000 ml of dry toluene under nitrogen. The mixture is stirred for a further 4 hours at room temperature and excess diisobutylaluminum hydride is decomposed with 120 ml of methanol. 1,000 ml of 10% strength hydrochloric acid are added, after which stirring is continued overnight at room temperature. The organic phase is separated off and the aqueous phase is extracted several times with toluene. The combined organic phases are washed with water and then dried over Na.sub.2 SO.sub.4. Removal of the solvent gives 109 g of the aldehyde (n.sub.D.sup.22 : 1.5621).

300 MHz NMR spectrum in CDCl.sub.3 : .delta. [ppm]=1.63-1.82(4H); 2.14(4H); 2.59(3H); 2.55(1H); 7.28(2H); 7.67(1H); 10.29(1H).

The novel benzaldehydes stated in Table 3 below were prepared by the process described above and are characterized by the physical properties stated; the other compounds in Table 3 can readily be obtained using corresponding starting materials.

TABLE 3__________________________________________________________________________Benzaldehydes ##STR53## IbExample R.sup.1 R.sup.2 X Physical Properties__________________________________________________________________________66 CH.sub.3 1-Cyclohexenyl H n.sub.D.sup.22 = 1.562167 CH.sub.3 Cyclopentyl H68 CH.sub.3 1-Cyclopentenyl H69 C.sub.2 H.sub.5 Cycloheptyl H70 CH.sub.3 Cyclopropyl H71 CH.sub.3 Cyclohexyl 5-Cl72 CH.sub.3 Cyclohexyl H mp. 42-45.degree. C.73 CH.sctn. Norbornen-2-yl H74 CH.sctn. 2,5-Norbornadien-2-yl H75 CH.sub.3 ##STR54## H76 CH.sub.3 ##STR55## H77 CH.sub.3 CH(C.sub.2 H.sub.5).sub.2 H 300-MHz-NMR-spectrum in CDCl.sub.3 : .delta. [ppm] = 0.77(6H); 1.56(2H); 1.72(2H); 2.64(3H); 2.91(1H); 7.37(2H); 7.63(1H); 10.33(1H)78 CH.sub.3 ##STR56## H 250-MHz-NMR-spectrum in CDCl.sub.3 : .delta. [ppm] = 0.86(3H); 1.22(3H); 1.62(2H); 2.64(3H); 3.04(1H); 7.33(1H); 7.44(1H); 7.63(1H); 10.35(1H)79 C.sub.2 H.sub.5 ##STR57## H80 cis/trans CH.sub.3 ##STR58## H 200-MHz-NMR-spectrum in CDCl.sub.3 : .delta. [ppm] = 0.89 and 0.97(3H); 1.36 and 1.8(3H); 2.25 and 2.37(2H); 2.52 and 2.57(3H); 5.33 and 5.64(1H); 7.22-7.4(2H); 7.73(1H)81 CH.sub.3 ##STR59## H82 CH.sub.3 ##STR60## H83 CH.sub.3 ##STR61## H84 CH.sub.3 Isopropyl H 300-MHz-NMR-spectrum in CDCl.sub.3 : .delta. [ppm] = 1.27(6H); 2.66(3H); 3.3(1H); 7.33(1H); 7.5(1H); 7.65(1H); 10.32(1H)85 CH.sub.3 Isopropyl 5-F86 CH.sub.3 n-Propyl H87 CH.sub.3 n-Butyl H88 CH.sub.3 ##STR62## H89 C.sub.2 H.sub.5 Isopropenyl H90 CH.sub.3 Isopropenyl H 200-MHz-NMR-spectrum in CDCl.sub.3 : .delta. [ppm] = 2.01(3H); 2.6(3H); 4.85(1H); 5.26(1H); 7.35(2H); 7.73(1H); 10.33(1H)91 CH.sub.3 1,3-Cyclohexadienyl H92 CH.sub.3 Vinyl H93 CH.sub.3 ##STR63## H94 CH.sub.3 Norborn-2-yl H 200-MHz-NMR-spectrum in CDCl.sub.3 : .delta. [ppm] = 1.17-174(7H); 1.96(1H); 2.39(2H); 2.68(3H); 3.53(1H); 7.37(1H); 7.52(1H); 7.69(1H); 10.38(1H)132 CH.sub.3 ##STR64## H 300-MHz-NMR-spectrum in CDCl.sub.3 : .delta. [ppm] = 0.68(3H); 1.42(6H); 1.86(2H); 2.8(3H); 7.27(1H); 7.57(1H) 7.66(1H); 10.38(1H)__________________________________________________________________________

EXAMPLES 95 TO 130

Preparation of the benzyl alcohols Ia

3-(1'-cyclohexenyl)-2-methylbenzyl alcohol

A solution of 24 g (0.12 mole) of 3-(1'-cyclohexenyl)-2-methylbenzaldehyde in 120 ml of ethanol is added dropwise to a suspension of 2.3 g (0.06 mole) of sodium borohydride in 120 ml of ethanol at room temperature. The mixture is stirred for 15 hours at room temperature, after which 320 ml of 5% strength hydrochloric acid are carefully added and extraction is carried out several times with ether. The combined ether phases are washed with 5% strength hydrochloric acid and then with water, dried and evaporated down. 23 g of 3-(1'-cyclohexenyl)-2-methylbenzyl alcohol of melting point 62-64.degree. C. (Example 95) are obtained. 3-Sec-butyl-2-methyl-alpha-ethynylbenzyl alcohol

50 ml of THF (absolute) are saturated with acetylene at 0.degree. C. and under a ntirogen atmosphere. 87 ml of methylmagnesium chloride solution (1.5 molar) are added dropwise in the course of 45 minutes with further introduction of acetylene, and the mixture is stirred for 30 minutes at 0.degree. C. At -20.degree. C., a solution of 15.3 g of 3-sec-butyl-2-methylbenzaldehyde in 20 ml of THF (absolute) is added dropwise. Stirring is continued for 2 hours at -20.degree. C., and the reaction mixture is allowed to stand overnight at room temperature and is poured into 300 ml of ice water. It is acidified with dilute hydrochloric acid and then extracted three times by shaking with ether. The combined ether extracts are washed with water, dried over sodium sulfate and evaporated down to give 16.6 g of an oil (70% of desired compound) which, after purification by column chromatography over silica gel using toluene as the mobile phase, gives 5.1 g of the pure benzyl alcohol (Example 96).

300 MHz NMR spectrum in CDCl.sub.3 : .delta.][ppm]=0.84 (3H); 1.17(3H 1.57(2H); 2.36(3H); 2.57(1H); 2.62(1H); 2.97(1H); 5.62(1H); 7.18(2H); 7.52(1H).

3-Cyclopropyl-2-methylbenzyl alcohol

(a) Dihalocarbene addition: 10 ml of methylene chloride, 0.42 ml of ethanol, 0.14 g of benzyltriethyl-ammonium chloride and 20.9 g (0.083 mole) of bromoform are added to 9.9 g (0.042 mole) of 2-methyl-3-vinylbenzyl tetrahydro-2-pyranyl ether. After the addition of 13.28 g (0.166 mole) of ice-cold 50% strength NaOH, thorough stirring is carried out for 1 hour at room temperature and for 8 hours at 50.degree. C. The reaction mixture is poured into 300 ml of water and is extracted three times with methylene chloride. The combined extracts are dried and evaporated down. Purification by column chromatography over silica gel using toluene as the mobile phase gives 9.1 g of 3-(2',2'-dibromocyclopropyl)-2-methylbenzyl tetrahydro-2-pyranyl ether.

250 MHz NMR spectrum in CDCl.sub.3 : .delta. [ppm]=1.45-1.95(6H); 2.02(1H); 2.15(1H); 2.46(3H); 2.84(1H); 3.55(1H); 3.9(1H); 4.55(1H); 4.72(1H); 4.88(1H); 6.93(1H); 7.14(1H); 7.37(1H).

(b) Dehalogenation: 45.2 g (0.155 mole) of tri-n-butyltin hydride are added, at 0.degree. C., to 29.7 g (0.074 mole) of the dibromocyclopropyl compound prepared under a) and 150 ml of n-hexane. The mixture is stirred for 1 hour at room temperature and for 10 hours under reflux. It is refluxed for a further 20 hours, a total of 15 g of tri-n-butyltin hydride being added a little at a time. The cooled reaction solution is evaporated down. Purification by column chromatography over silica gel using toluene as the mobile phase gives 17.1 g of 3-cyclopropyl-2-methylbenzyl tetrahydro-2-pyranyl ether.

200 MHz NMR spectrum in CDCl.sub.3 : .delta. [ppm]=0.62(2H); 0.91(2H); 1.5-2.0(6H+1H); 1.94(3H) 3.6(1H); 3.97(1H); 4.52(1H); 4.76(1H); 4.87(1H); 7.02.7.21(2H); 7.29(1H).

(c) Elimination of the protective group: 16.7 g of 3-cyclopropyl-2-methylbenzyl tetrahydro-2-pyranyl ether in 180 ml of methanol are stirred overnight at room temperature with 10.8 ml of concentrated hydrochloric acid. The mixture is neutralized with sodium methylate solution while cooling with ice and is then evaporated down. Water is added to the residue, which is then extracted several times with ether. The combined ether extracts are washed with water, dried and evaporated down. The crude product (11.5 g) is purified by column chromatography over silica gel using toluene as the mobile phase. 8.9 g of 3-cyclopropyl-2-methylbenzyl alcohol (Example 100) are obtained.

300 MHz NMR spectrum in CDCl.sub.3 : .delta. [ppm]0.61(2H); 0.93(2H); 1.88(1H); 2.15(1H); 2.43(3H); 4.63(2H); 6.97-7.19(3H).

The novel benzyl alcohols stated in Table 4 below were prepared by the processes described in Preparation Examples 95, 96 and 100 and are characterized by the physical properties stated; the other compounds in Table 4 can readily be obtained using corresponding starting materials.

TABLE 4__________________________________________________________________________Benzyl alcohols of the formula Ia ##STR65## IaExample R.sup.1 R.sup.2 R.sup.3 X Physical properties__________________________________________________________________________ 95 CH.sub.3 1-Cyclohexenyl H H mp. 62 to 64.degree. C. 96 CH.sub.3 sec-Butyl Ethynnyl H 300-MHz-NMR-spectrum in CDCl.sub.3 : .delta. [ppm] = 0.84(3H); 1.17(3H); 1.57(2H); 2.36(3H); 2.57(1H); 2.62(1H); 2.97(1H); 5.62(1H); 7.18(2H); 7.52(1H) 97 CH.sub.3 Cyclopentyl H H 98 CH.sub.3 1-Cyclopentenyl H H 99 CH.sub.3 1-Cyclopentenyl Ethynyl H100 CH.sub.3 Cyclopropyl H H 300-MHz-NMR-spectrum in CDCl.sub.3 : .delta. [ppm] = 0.61(2H); 0.93(2H); 1.88(1H); 2.15(1H); 2.4(3H); 4.63(2H); 6.97-7.19(3H)101 CH.sub.3 Cyclohexyl H 5-Cl102 CH.sub.3 Cyclohexyl H H mp. 87-88.degree. C.103 CH.sub. 3 Cyclohexyl Ethyl H104 CH.sub.3 2-Norbornen-2-yl H H105 CH.sub.3 2,5-Norborna- H H dien-2-yl106 CH.sub.3 Norborn-2-yl H H 200 MHz-NMR-spectrum in CDCl.sub.3 : .delta. [ppm] = 1.21-1.73[7H + 1H(OH)]; 1.94(1H); 2.37(3H + 2H); 3.5(1H); 4.77(2H); 7.26(3H)107 CH.sub.3 CH(C.sub.2 H.sub.5).sub.2 H H 200-MHz-NMR-spectrum in CDCl.sub.3 : .delta. [ppm] = 0.79(6H); 1.49-1.8(4H); 1.7(1H); 2.34(3H); 2.85(1H); 4.74(2H); 7.21(3H);108 CH.sub.3 Isopropyl H H 300-MHz-NMR-spectrum in CDCl.sub.3 : .delta. [ppm] = 1.22(6H); 2.24(1H); 2.31(3H); 3.22(1H); 4.63(2H); 7.12-7.24(3H)109 CH.sub.3 Isopropyl CH.sub.3 H 300-MHz-NMR-spectrum in CDCl.sub.3 : .delta. [ppm] = 1.22(6H); 1.43(3H); 2.27(3H); 2.45(1H); 3.21(1H); 5.14(1H); 7.19(2H); 7.35(1H);110 CH.sub.3 Isopropyl H 5-Cl111 CH.sub.3 Isopropyl Ethynyl H112 CH.sub.3 ##STR66## H H113 CH.sub.3 n-Propyl H H114 CH.sub.3 n-Butyl H H115 CH.sub.3 Isopropenyl H H 200-MHz-NMR-spectrum in CDCl.sub.3 : .delta. [ppm] = 1.83(1H); 2.0(3H); 2.28(3H); 4.71(2H); 4.82(1H); 5.2(1H); 7.05-7.33(3H)116 CH.sub.3 Isopropenyl Ethynyl H117 CH.sub.3 Isopropenyl CN H118 CH.sub.3 Isopropenyl Vinyl H 200-MHz-NMR-spectrum in CDCl.sub.3 : .delta. [ppm] = 2.02(3H); 2.13(broad, 1H); 2.33(3H); 4.85(1H); 5.19-5.5(4H); 5.97-6.14(1H); 7.07(1H); 7.2(1H); 7.4(1H)119 CH.sub.3 ##STR67## H H120 CH.sub.3 ##STR68## H H121 CH.sub.3 ##STR69## H H n.sub.D.sup.22 : 1.5325122 CH.sub.3 ##STR70## H H 200-MHz-NMR-spectrum in CDCl.sub.3 : .delta. [ppm] = 0.88(3H); 1.22(3H); 1.64(2H); 1.86(H); 2.33(3H); 3.0(1H); 4.72(2H); 7.22(3H)123 CH.sub.3 CH(C.sub.2 H.sub.5).sub.2 Isopropyl H124 C.sub.2 H.sub.5 ##STR71## H H125 CH.sub.3 ##STR72## H H126 CH.sub.3 ##STR73## H H127 CH.sub.3 3,5-Diethyl- H H cyclohexyl128 CH.sub.3 ##STR74## H H129 CH.sub.3 Vinyl H H 300-MHz-NMR-spectrum in CDCl.sub.3 : .delta. [ppm] = 1.97(1H); 2.29(3H); 4.65(2H); 5.3(1H); 5.58(1H); 6.93-7.04(1H); 7.11-7.28(2H); 7.4(1H) Schmp.: 38-43.degree. C.130 CH.sub.3 ##STR75## H H 300-MHz-NMR-spectrum in CDCl.sub.3 : .delta. [ppm] = 0.67(3H); 1.39(6H); 1.83(2H + 1H); 2.46(3H); 4.66(2H); 7.09-7.31(3H)__________________________________________________________________________

Claims

1. A benzaldehyde of the formula I ##STR76## wherein R.sup.1 is methyl or ethyl, R.sup.2 is alkyl, alkenyl, cycloalkyl, cycloalkenyl, bicycloalkyl, bicycloalkenyl, or C.sub.1 -C.sub.5 -alkyl-substituted cycloalkyl, cycloalkenyl, bicycloalkyl or bicycloalkenyl, X is hydrogen, chlorine or fluorine and Z is CHO, with the proviso that R.sup.2 is not methyl when R.sup.1 is methyl or ethyl.

2. The benzaldehyde of claim 1, wherein X is hydrogen.

3. The benzaldehyde of claim 1, wherein X is chlorine.

4. The benzaldehyde of claim 1, wherein X is fluorine.

5. The benzaldehyde of claim 1, wherein R.sup.1 is methyl.

6. The benzaldehyde of claim 1, wherein R.sup.1 is ethyl.

7. The benzaldehyde of claim 1, wherein R.sup.2 is alkyl.

8. The benzaldehyde of claim 1, wherein R.sup.2 is alkenyl.

9. The benzaldehyde of claim 1, wherein R.sup.2 is cycloalkyl.

10. The benzaldehyde of claim 1, wherein R.sup.2 is cycloalkenyl.

11. The benzaldehyde of claim 1, wherein R.sup.2 is bicycloalkykl.

12. The benzaldehyde of claim 1, wherein R.sup.2 is bicycloalkenyl.

13. The benzaldehyde of claim 1, wherein R.sup.2 is C.sub.1 14 C.sub.5 alkyl substituted cycloalkyl.

14. The benzaldehyde of claim 1, wherein R.sup.2 is C.sub.1 -C.sub.5 alkyl substituted cycloalkenyl.

15. The benzaldehyde of claim 1, wherein R.sup.2 is C.sub.1 -C.sub.5 alkyl substituted bicycloalkyl.

16. The benzaldehyde of claim 1, wherein R.sup.2 is C.sub.1 -C.sub.5 -alkyl substituted bicycloakenyl.