Process for preparing condensation products

Abstract

A condensation according to the following equation ##STR1## is carried out in the presence of a dialkyl boryl carbonxylate, e.g. diethyl boryl pivalate. High yields are obtained.

Description

In application in which one of us is an applicant, Ser. No. 297,146, filed Dec. 10, 1972, dialkyl boryl carboxylates are employed in the protolyses of trialkyl boranes and compounds containing protons.

This invention relates to a process for the production of aldol condensates and in particular a process for the production of substituted vinyl ketones and vinyl aldehydes with the use of novel condensing agents.

In accordance with the invention, carbonyl compounds RCH.sub.2 COR' (A) wherein R is H, alkyl or aryl and R' is hydrogen, alkyl or aryl are condensed with themselves (reaction type I) or with other carbonyl compounds R"COR" (B) wherein R" and R"' are H, alkyl or aryl (reaction type II) to form condensation products (C). R and R', or R" and R"', or R' and R"', or R' and R" , or may also be linked together.

The condensing agents used for the reactions are dialkyl boryl carboxylates having the general formula R.sub.2.sup.V BOCOR.sup.IV wherein R.sup.IV stands for C.sub.1 -C.sub.6 hydrocarbons and R.sup.V for C.sub.1 -C.sub.4 hydrocarbons. The use of the liquid diethyl boryl pivalate (R.sup.V = ethyl; R.sup.IV is t-butyl) is particularly advantageous, but also the other, e.g., solid diethyl boryl carboxylates, e.g., from acetic acid, butyric acid, 3,3-dimethyl butyric acid, cyclopropane carboxylic acid and benzoic acid may be used.

The condensations of A and B by means of the dialkyl boryl carboxylates used in accordance with the invention are described by the general equation (a): ##STR2## The cleavage of water corresponds to the reaction of the dialkyl boryl carboxylates according to the equation (b), e.g., ##STR3## The oxides produced of the equation (b) are generally readily separated. The solid bis-[ethyl-pivaloyloxy-boryl]-oxide can be distilled off particularly readily. Moreover, its filtration to separate it is also well suited.

The carbonyl compounds of the type A are capable of reacting with themselves (reaction type I). In accordance with the invention, ketones and aldehydes having one alpha-CH.sub.2 group or ketones having two alpha-CH.sub.2 groups as well as diketon and keto aldehydes having one to three alpha-CH.sub.2 groups are suitable as component A:

Rch.sub.2 cor', e.g., with R = hydrogen or alkyl such as methyl, ethyl propyl, butyl and R' = R or isopropyl, t-butyl, phenyl, subst. phenyl (o-, p-, m-methyl, chlorine, hydroxyl, acetoxy, amino) Rch.sub.2 coch.sub.2 coch.sub.2 r', e.g., with R = hydrogen R' = hydrogen The ketoaldehyde RCH.sub.2 COCH.sub.2 C(O)H can also be used.

One mole of the component B reacts per 1 mole of alpha-CH.sub.2 groups of A. Suitable A components also include cyclic ketones (linkage of R and R') of various ring sizes OC(CH.sub.2).sub.n wherein n is 4 to 15 and more. Purely aliphatic ring ketones such as cyclopentanone (n = 4) or cyclopentadecanone (n = 14) and unsaturated ring ketones (2-cyclohexenone and isophorone) a also well suited for the process according to the invention. The A components may also bear various substituents on R or R'. Sterically rigid ketones such as camphor or norbornanone may also be used for the purposes of the invention.

Particularly useful as B component for the reaction type II are the non-enolizable aldehydes and ketones. For example, benzaldehyde, pivaladehyde, benzophenone, adamantano fluorenone, and benzylidene acetophenone have been found to be suitable.

In the reactions of the type II, linking of the compound A with a plurality of compounds B may also occur according to the invention if the component A contains two or more alpha-CH.sub.2 groups. Diketones such as diacetyl, dimedone or acetyl acetone react in a completely analogous manner as A component. Finally, the resultant compounds of the type C may also further react as A or B components according to the process of the invention, in the case of A, if they contain vinylogous alpha-CH.sub.2 groups, in which case in C (equation (a)), R'" is CH.sub.2 R.sup.VI.

The reactions in accordance with the invention proceed at atmospheric pressure or reduced or elevated pressures, and, in most cases, commence at as low as 20.degree. or above 20.degree. C. Above 80.degree. C, the reaction rate is high. The temperature range between 80.degree. and 150.degree. C. is optimum. The exothermic reactions then lead smoothly and almost quantitative to the compounds of the C type. These are generally obtained directly in pure form or as E/Z isomer mixture (E = opposite, Z = same side according to the directives of IUPAC nomenclature). Additional purification may be effected, for example, by boiling up for a short period of time in methanol. However, distillation or recrystallization are not necessary for purification in most cases.

The reactions can also be readily carried out in various solvents such as aliphatic or aromatic hydrocarbons or in ethers or halogenated hydrocarbons. Toluene or xylene are very useful for obtaining crystalline condensation products C.

As compared with the previously usual possibilities of aldol condensations, the reactions according to the invention offer substantially more possibilities of C--C linkage. By means of the process, also unsaturated carbonyl compounds such as cyclohexenone can be readily condensed. Moreover, markedly higher yields as compared with those obtained with known condensing agents are obtained. Functional groups such as, for example, chlorine, hydroxyl or amino groups do not interfere. For example, high yields of dimers of acylophenones which are appropriately substituted in the phenyl nucleus are obtained. Additionally, the products always are of substantially higher purity than those obtained with the use of the previously usual condensing agents.

The following summary of the condensates C which are obtainable according to the invention by reaction type I and reaction type II illustrates the possible variations of the process according to the invention. ##STR4##

EXAMPLES

Condensation by the reaction type I (A = B)

Dimeric condensation products from alkyl phenyl ketones (see Tables 1 and 2) 5-Benzoyl-6-undec-5-en (Z/E) from caprophenone:

Diethyl boryl pivalate (33.4 g., 197 mmoles) is added dropwise at 90.degree. C. within about 2 hours to 1-oxo-1-phenylhexane (caprophenone; 34.5 gram mmoles) while stirring. While the mixture turns faintly yellow, ethane is evolved (4.36 std.liters 99%). Thereafter bis-[ethyl-pivaloyl-oxy-boryl]-oxide (28.2 g., 97%) is distilled off in vacuum from the clear yellowish liquid. residue is mixed with methanol (100 ml.) and all readily volatile constituents are distilled off. A Z/E isomer mixture is isolated as a liquid yellowish borine-free residue. Yield, 31.3 g (95%); purity (by gas chromatography) 97%.

Table 1__________________________________________________________________________Dimeric condensation products from alkyl phenyl ketones(Acylophenones) Dimeric condensates 1 to 5Alkyl phenyl Yield Purity Consecutiveketone (%) (%) Characteristic No.__________________________________________________________________________Acetophenone 72.sup.a 98 liquid, yellow 1Propiophenone 97 98 liquid, yellowish 2Butyrophenone 96 99 liquid, yellowish 3Valerophenone 96 96 liquid, yellowish 4Caprophenone 95 97 liquid, yellowish 5__________________________________________________________________________ .sup.a The residue consists of trimeric and tetrameric condensates depending upon the mode of operation. Table 2__________________________________________________________________________Dimeric condensates from substituted acetophenones Dimeric condensates 6-9Substituted Yield Purity ConsecutiveAcetophenone (%) (%) Characteristic No.__________________________________________________________________________2-Chloroacetophenone 82 92 viscous, green 64-Acetoxy-acetophenone 74 >95 liquid, orange 74-Hydroxy- solid brownacetophenone 77 >95 powder 82-4-Dimethyl-acetophenone 73 99 liquid, yellow 9__________________________________________________________________________

To 18.2 g. (100 mmoles) of cyclododecanone in 100 ml., of toluene are added dropwise at 100.degree. C. within about 50 minutes 17.7 g. (104 mmoles) of diethyl boryl pivalate. 2.58 Std.liters (115 mmoles) of ethane (MS) are cleaved off. After the diluent, 15.9 g. (53 mmoles) of bis(ethyl-pivaloyloxyboryl)oxide having a boiling point of 55.degree.-60.degree. C/0.1 mm are distilled off from the solid white mixture to give 16.2 g. of a white crystalline residue (found, 0.2% B). After boiling-up in 100 ml. of methanol, the readily volatile constituents are distilled off to give 15.5 g. (44.8 mmoles) of a condensate having a melting point of 132.degree.-134.degree. C.

To 14.5 g. (109.3 mmoles) of indanone are added dropwise at 100.degree. to 110.degree. C. within about 1 hour 18.2 g. (107 mmoles of diethyl boryl pivalate. While the mixture assumes a faint yellowish color, 2.15 std.liters (96 mmoles) of ethane (MS) are evolved. The mixture solidifies when allowed to cool. Vacuum distillation gives 14.5 g. (49 mmoles) of bis(ethylpivaloyloxy-boryl)-oxide having a boiling point of 48.degree.-75.degree. C./0.1mm and 13.5 g. of raw condensate as a solid residue. After washing with heptane, 12.8 g. (52.3 mmoles) of condensate having a melting point of 126.degree. to 129.degree. C. are obtained.

Table 3__________________________________________________________________________Dimeric condensates from cyclic ketones Dimeric condensates 10-16 Yield Purity ConsecutiveCycloketone (%) (%) Characteristic No.__________________________________________________________________________Cyclooctanone 92 95 liquid, yellowish 10Cyclododecanone 90 95 solid, white, 11 m.p. 132-134.degree. C2-Cyclohexenone 91 99 liquid, yellow 12Isophorone 89 99 viscous, yellow 131-Tetralone 90 100 solid, yellowish 14 m.p. 132-133.degree. C.1-Indanone 96 99 solid, yellowish 15 m.p. 126-129.degree. CCamphor.sup.a 89 98 solid, white 16 m.p. 55-56.degree. C.__________________________________________________________________________ .sup.a At 150.degree. C. about 50% conversion in 4 hours. Dimeric condensates C by reaction type I from steroid ketones (see Table 4) General prescription:

3 to 5 Millimoles of steroid ketone in a 3- to 4 fold excess of diethyl boryl pivalate are heated for about 30 minutes without a diluent or in the presence of about 50 ml. of xylene to 120.degree.-130.degree. C. While heating, 6 to 10 mmoles of ethane (MS) are evolved. Thereafter the readily volatile constituents are distilled off using finally vaccum of 0.1 Torr (bath of 100.degree. C.). The residue is mixed with 50 ml. of methanol. After having removed the borin-containing constituents by distillation (bath of 100.degree. C., 0.1 Torr), the corresponding crystalline condensates are obtained.

Table 4__________________________________________________________________________ Dimeric Condensates 17-20 Yield Purity ConsecutiveKetone (%) (%) Characteristic No.__________________________________________________________________________Androsterone 97 >95 solid, colorless 17 m.p. >220.degree. C.Epiandrosterone 95 >95 solid, colorless 18 m.p. >220.degree. C.Dehydro- 95 >95 solid, colorless 19epiandrosteron m.p. >220.degree. C.Testosterone 98 >95 solid, yellow 20 m.p. >220.degree. C.__________________________________________________________________________ Condensation by reaction type II (A .noteq. B) Benzaldehyde and ketones with an alpha-CH.sub.2 group (see Table 5) General prescription:

To a mixture of 30 to 80 mmoles of ketone and 40 to 100 mmoles of benzaldehyde are added dropwise at about 120.degree. C. while thoroughly stirring 60 to 160 mmoles of diethyl boryl pivalate. While the liquid mixture changes its color, 60 to 160 mmoles of ethane with at most 1 to 5% of ethylene are evolved. The mixture is maintained at 20.degree. C for further 30 minutes until gas evolution has ceased. Then by distillation 10 to 20mmoles of excess benzaldehyde are removed and afterwards by vacuum distillation 30 to 80 mmoles of bis(ethyl-pivaloyloxy-boryl)oxide boiling at 65.degree. to 85.degree. C/0.1 Torr. The residue (30 to 80 mmoles) is mixed with about 100 to 200 ml of methanol. The boron-containing constituents and traces of pivalic acid are finally removed by vacuum distillation (0.1 Torr). Solid condensates can be recrystallized from methanol or heptane.

Dehydroepiandrosterone and benzaldehyde:

From 2.8 g. (9.7 mmoles) of hormone, 2 g. (18.9 mmoles of benzaldehyde, and 5.5 g. (32.3 mmoles) of diethyl boryl pivalate there after 15 min. are obtained 663 std.ml (29.6mmoles of pure ethane (MS) and 2.7 g. (9.06 mmoles) of bis(ethylpivaloyloxy-boryl)oxide. After having mixed the yellow residue with 50 ml. of methanol, 3.5 g. (9.3 mmoles) of condensate having a melting point of 164.degree. C. are isolated.

1-Tetralone and benzaldehyde:

From 5.6 g. (33.4 mmoles) of tetralone, 4.1 g. (38.7 mmoles) of benzaldehyde, and 11.9 g. (70 mmoles) of diethyl boryl pivalate there after 1 h are obtained 1.62 std.liters (72.3 mmoles) of pure ethane (MS) and 9.7 g. (33 mmoles) of bis(ethyl-pivaloxy-boryl)oxide. From the orange residue are obtained with 2 .times. 50 ml. of methanol 7.5 g. (32.1 mmoles) of 97% (GC) yellow E condensation having a melting point of 96.degree. C.

2-cyclohexenone and benzaldehyde

6.6 Grams (68.7 mmoles) of cyclohexanone, 8.7 g. (82.1 mmoles) of benzaldehyde and 24.5 g. (144.2 mmoles) of diethyl boryl pivalate split off at 120.degree. C. within 1.5 hours 3.23 std. liters (144 mmoles) of 98% (MS) ethane. From the orange mixture are removed 20.8 g. (69.8 mmoles) of bis(ethylpivaloyloxy-boryl)oxide by distillation. After admixture with 2 .times. 50 ml. of methanol and removal of all readily volatile constituents by distillation, 11.8 g. (64 mmoles) of 97% (GC) of yellow viscous E condensate are obtained.

Butyrophenone and benzaldehyde:

7.4 g. (50 mmoles) of butyrophenone, 7.5 g. (70.8 mmoles) of benzaldehyde, and 19.2 g. (112.8 mmoles) of diethyl boryl pivalate give after 1.5 hours a yellowish mixture from which 1.28 std.liters (57.1 mmoles) of 97% (MS) ethane have cleaved off. 14.5 Grams (48.6 mmoles) of bis(ethyl-pivaloyloxy-boryl)oxide are distilled off. After addition of 2 .times. 50 ml. of methanol, 11.2 g. (47 mmoles) of Z/E condensate (.about.1:1) (GC) are obtained.

Table 5__________________________________________________________________________Cocondensation products C from benzaldehyde (B) and ketones (A)with a methylene or methyl group in alpha position (reactiontype II). Cocondensation products 21-36 Yield Purity ConsecutiveKetone (A) (%) (%) Characteristic No.__________________________________________________________________________Methyl isopropyl 59 99 liquid, yellowish 21ketonet-Butylmethyl ketone 63 100 solid, colorless 22(Pinacoline) m.p. 33acetophenone 38.degree. C.2-Methyl cyclohexanone 90 98 viscous, yellow 232-Cyclohexenone 93 97 viscous,yellow 241-Indanone 99 98 solid, yellow 25 m.p. 110.degree. C.1-Tetralone 96 97 solid, yellow 26 m.p., 96.degree. C.Dehydro-epi- 96 >95 solid, colorless 27androsterone m.p., 164.degree. C.Acetophenone 96 99 solid, yellow 28 m.p., 55.degree. C.Propiophenone 96 99 viscous, yellowish 29Butyrophenone 94 100 viscous, yellowish 30Valerophenone 94 100 viscous, yellowish 31Caprophenone 95 100 viscous, yellowish 322,4-Dimethyl- 97 98 viscous, yellow 332-Chloroacetophenone 96 >95 viscous, yellow- 34 green2-Hydroxy-acetophenone 88 >95 solid, brown 35 powder4-Acetoxy acetophenone 89 >95 solid, yellowish 36 m.p., 60.degree. C.__________________________________________________________________________ 2:1 cocondensates of ketones having two alpha-methylene or alpha-methyl groups and benzaldehyde (see Table 6) General procedure

To a mixture of 30 to 80 mmoles of ketone and 100 to 400 mmoles of benzaldehyde are added dropwise while thoroughly stirring at about 120.degree. C. 130 to 360 mmoles of diethyl boryl pivalate. While the mixture changes its color, 130 to 360 mmoles of ethane with at most 1 to 5 % of ethylene are evolved. After processing there are obtained (see above) 280 to 780 mmoles of condensation product and in addition 70 to 180 mmoles of bis(ethyl-pivaloyloxy-boryl)oxide.

Acetone and benzaldehyde

From 4.3 g. (74.2 mmoles) of acetone, 23 g. (217 mmoles of benzaldehyde and 52 g. (306 mmoles) of diethyl boryl pivalate an orange mixture is obtained after 3 hours. 5.5 Std.liter (246 mmoles) of 95% (MS) ethane are split off. 36 Grams (120.5 mmoles) of bis(ethyl-pivaloyloxyboro)oxide are distilled off. After having added 2 .times. 50 ml. of methanol, 14.5 g. (61.7 mmoles) of 98.5% (GC) orange, very viscous EE condensate are obtained.

Cyclopentanone and benzaldehyde

A mixture of 6.3 g. (75 mmoles) of cyclopentanone, 19.9 g. (187.5 mmoles) of benzaldehyde and 52.2 g. (307 mmoles) of diethyl boryl pivalate is heated in 100 ml. of toluene for 3 hours. After 6.6 Std. liters (295 mmoles) of pure (MS) ethane have split off, 42 g. (140.1 mmoles) of bis(ethylpivaloyoxyboro)oxide are distilled off. The yellow-orange residue is mixed with 2 .times. 50 ml. of methanol whereupon all readily volatile constituents are distilled off. After recrystallization from methanol, 17.2 g. (66 mmoles) of a pure (CC) yellow EE condensate having a melting point of 196.degree. C. are obtained from 19.8 g. of raw condensate.

Table 6__________________________________________________________________________2:1 Cocondensate C of benzaldehyde B and ketones A havingtwo methylene or methyl groups 2:1 Cocondensation product 37-42 Yield Purity ConsecutiveKetone (A) (%) (%) Characteristic No.__________________________________________________________________________Acetone 83 99 viscous, orange 372-Butanone 81 94 viscous, orange 38 (+10).sup.a3-Pentanone 71 96 viscous, brown 39 (+12).sup.aCyclopentanone 88 100 crystalline, needle- 40 shaped, yellow m.p., 196.degree. C.Cyclohexanone 95 99 crystalline, yellow 41 m.p., 107-113.degree. C.Cyclododecanone 84 >95 viscous, yellow 42__________________________________________________________________________ .sup.a 1:1 condensate Condensation by reaction type II from camphor (A) and different carbonyl compounds of the type B (see Table 7) Camphor and fluorenone:

A mixture of 8 g. (52 mmoles) of camphor, 10.5 g. (58.3 mmoles) of fluorenone, and 22.8 g. (134 mmoles) of diethyl boryl pivalate is heated for 3 hours to 150.degree. C. While the mixture assumes an orange color, 2.62 std.liters (117 mmole of pure (MS) ethane are split off. The readily volatile constituents among which are 14 g. (46.9 mmoles) of bis(ethylpivaloyloxyboro)oxide are distilled off under vacuum (to 95.degree. C./0.1 Torr). 17 Grams of a yellow residue are mixed with 2 .times. 50 ml. of methanol and the boron-containing constituents and traces of pivalic acid are distilled off, finally under vacuum (bath of 100.degree. C.) to give 15.5 g. (49.3 mmoles) of 99% (GC) yellow solid condensate having a melting point of 50.degree. to 54.degree. C.

Table 7__________________________________________________________________________Cocondensation products C from camphor (A) and carbonylcompounds (B) Cocondensates 43-48Carbonyl Yield Purity Consecutivecompound (B) (%) (%) Characteristic No.__________________________________________________________________________Pivalaldehyde 89 100 liquid, colorless 432-Adamantanone 90 99 solid, colorless 44 m.p., 85.degree. C.Benzaldehyde 92 100 viscous, yellow 45Benzophenone 90 92 solid, yellow 46 m.p., 100-106.degree. C.Fluorenone 94 99 solid, yellow 47 m.p., 50-54.degree. C.Chalcone 92 92 solid, yellow 48 m.p., 110-112.degree. C.__________________________________________________________________________ Condensation by reaction type II of different carbonyl compounds A and B (see Tables 8 to 10) General procedure

To a mixture of 0.2 to 0.6 moles of carbonyl compound of type B and 0.2 mole (per mole of alpha-CH.sub.2 in A) of diethyl boryl pivalate is added dropwise at 80.degree.-120.degree. C., a mixture of 0.1 mole of carbonyl compound type A and carbonyl compound type B. For each alpha-CH.sub.2 group of A are formed 0.2 mole of ethane and 0.1 mole of bis[ethyl-pivaloyloxoboro]oxide. After having distilled off the excess B and the oxide, the compound C is obtained almost quantitatively as residue.

Table 8__________________________________________________________________________Cocondensation products (C) 49 to 54 from different aldehydes(A) and (B) Condensation products CAldehyde Yield.sup.a PurityA B (%) (%) Characteristic No.__________________________________________________________________________Acetaldehyde Benzaldehyde 80 95 yellow, liquid 49Propanal Benzaldehyde 78 95 yellow, liquid 50Butanal Benzaldehyde 75 95 yellow, viscous 51Capronaldehyde Benzaldehyde 68 95 yellow, viscous 521-Valerialdehyde Benzaldehyde 74 95 yellow, viscous 532-Ethylbutanal Benzaldehyde 79 95 yellow, viscous 54__________________________________________________________________________ .sup.a The balance consists of higher condensation products. Table 9__________________________________________________________________________Cocondensation products (C) 55 to 64 from different ketones (A)and aldehydes (B) Condensation products CCarbonyl compound Yield PurityA B (%) (%) Characteristic No.__________________________________________________________________________1-Indanone Paraformaldehyde 85 95 yellowish, 55 liquid1-Tetralone Paraformaldehyde 89 90 yellowish, 56 liquidCamphor Paraformaldehyde 87 90 colorless, liquid 571-Indanone Pivaldehyde 91 95 yellow, viscous 58Propiophenone Pivaldehyde 85 95 yellow, viscous 59Dimedone Benzaldehyde 84 90 red, viscous 60Progesterone Benzaldehyde 98 95 yellow, solid 61Propiophenone 4-Hydroxy- 95 95 yellow, viscous 62 benzaldehyde.sup.aPropiophenone 3-Hydroxy- 94 95 yellow, viscous 63 benzaldehyde.sup.aPropiophenone 4-Amino- 96 95 yellow, viscous 64 benzaldehyde.sup.a__________________________________________________________________________ .sup.a Per mole of OH- or NH.sub.2 group, 1 mole of diethylboryl pivalate is additionally used and slowly added to the aldehyde at 80.degree. C. Thereafter, the reaction is carried out as described. Table 10__________________________________________________________________________Cocondensation products (C) 65 to 72 from differentketones (A) and (B) Condensation products CKetone Yield PurityA B (%) (%) Characteristic No.__________________________________________________________________________Acetophenone Benzophenone 85 96 orange, viscous 65Indanone Benzophenone 92 98 yellow, viscous 66Cyclohexanone Benzophenone 93 97 yellow, viscous 67Pinacoline Benzophenone 91 97 yellow, viscous 68Acetone Benzophenone 92 96 yellow, viscous 69Acetone Chalcone 90 92 orange, viscous 70Acetone Fluorenone 86 97 orange, solid 712-Methyl- Fluorenone 85 96 yellow, solid 72cyclohexanone__________________________________________________________________________ Homocondensation by means of different dialkyl boryl carboxylate

To 120 mmoles of carbonyl compound (A) is added dropwise at 100.degree.-110.degree. C. within about 1 hour a solution of 120 mmoles of dialkyl boryl carboxylate in 150 ml. of toluene. Thereby, 115-120 mmoles of ethane are liberated. After having distilled off the toluene under vacuum, about 60 mmoles of bis(alkyl-carboxyloxy)-diboroxane (boiling range, 70.degree.-95.degree. C./0.1 Torr) are obtained. The residue is mixed with 250 ml. of methanol and all of the readily volatile constituents are distilled off to give 52 to 59 mmoles (87-99%) of condensate C (see Table 11).

Table 11__________________________________________________________________________Homocondensation by means of different dialkyl boryl carboxylateCarbonyl Yield Puritycompound Condensing agent (%) (%) No.__________________________________________________________________________Propiophenone Diethylboryl acetate 91 96 2Caprophenone Diethylboryl acetate 89 97 5Cyclododecanone Diethylboryl acetate 92 95 11Propiophenone Diethylboryl propionate 93 97 2Cyclooctanone Diethylboryl propionate 91 96 10Propiophenone Diethylboryl-cyclo- 92 98 2 propane carboxylateCyclododecanone Diethylboryl-cyclo- 90 96 11 propane carboxylatePropiophenone Diethylboryl benzoate 90 97 2Cyclooctanone Diethylboryl benzoate 89 98 10Propiophenone Dipropylboryl pivalate 97 96 2Cyclooctanone Dipropylboryl pivalate 94 95 10__________________________________________________________________________ Cocondensation by means of different dialkylboryl carboxylates:

To a mixture of 50 mmoles of carbonyl compound (A) and about 150 mmoles of carbonyl compound (B) is added dropwise at 100.degree. to 110.degree. C. within about 1 hour a solution of 100 mmoles of dialkylboryl carboxylate in 150 ml. of toluene. About 100 mmoles of ethane are liberated. After having distilled off toluene and excess compound B, about 50 mmoles of bis(alkylcarboxyloxy)diboroxane (boiling range, 70.degree.-95.degree. C./0.1 Torr) are obtained. The residue is mixed with 250 ml. of methanol and the readily volatile constituents are distilled off to give 42-48 mmoles (84-96%) of condensate (see Table 12).

Table 12__________________________________________________________________________Cocondensation of A and B by means of different dialkyl borylcarboxylates Condensate CCarbonyl compound Yield PurityA B Condensing agent (%) (%) No.__________________________________________________________________________Cyclohexenone Benzaldehyde Diethylboryl acetate 92 96 24Butanal Benzaldehyde Diethylboryl acetate 67 92 51Pinacoline Benzaldehyde Diethylboryl acetate 94 93 221-Tetralone Benzaldehyde Diethylboryl propionate 92 95 26Isophorone Benzaldehyde Diethylboryl propionate 83 94 731-Indanone Benzaldehyde Diethylboryl cyclopropane 94 96 25 carboxylate2-Methylcyclohexanone Benzaldehyde Diethylboryl cyclopropane 91 97 23 carboxylate1-Tetralone Benzaldehyde Diethylboryl benzoate 93 94 26Methylisopropyl ketone Benzaldehyde Diethylboryl benzoate 50 95 211-Indanone Benzaldehyde Dipropylboryl pivalate 95 96 25Pinacoline Benzaldehyde Dipropylboryl pivalate 97 95 22Propiophenone Benzaldehyde Dipropylboryl pivalate 96 98 29__________________________________________________________________________

SUMMARY

Thus, the invention is concerned with a process for producing condensates wherein the following overall reaction is carried out: ##STR5##

The invention provides the improvement which comprises carrying out said reaction in the presence of a dialkyl boryl carboxylate of the formulaR.sub.2.sup.V BOCOR.sup.IV(D')

wherein R.sup.iv is C.sub.1 -C.sub.6 hydrocarbon, and R.sup.v is each C.sub.1 -C.sub.4 hydrocarbon.

R, R', R" and R'" can be of any size. In general they will be C.sub.1 to C.sub.30, and preferably are C.sub.1 - C.sub.18. As noted above, R, R', R" and R'" can be linked in various ways. Where the said substituents are linked, the resulting chains of the two substituents can contain C.sub.5 - C.sub.20 carbon atoms. As noted above R.sup.IV and R.sup.V are hydrocarbons, which can be saturated or unsaturated, e.g. olefinically unsaturated; they can be e.g. alkyl, alkylene, cycloalkyl, unsaturated cycloalkyl, or aryl.

The products according to the invention, as is well known, are useful for various purposes, for example in the production of polymeric colored oils and resins; as intermediates for the production of diols and dions which, for instance, are useful for polymerizations and oligomerizations; intermediates for complex components of various metal compounds; intermediates for the production of hydrocarbons otherwise accessible only with difficulty, by, for example reduction of materials produced according to the invention. Additionally, the process of the invention is useful for the introduction of certain functions at certain locations in the molecule, i.e. of keto-functions in .alpha.-position to original carbonyl functions. Also intermediates for the production of detergents can be produced.

The process is generally applicable to aldol condensations and thus can be used to make the myriad of known products, having known uses, produced by that reaction. The acrolein will at least partly react further as indicated at page 4, line 11-14. The invention can be used for production of benzalacetone by condensation of acetone and benzaldehyde; benzalacetophenone by condensation of acetophenone and benzaldehyde; phenylpropenal by condensation of benzaldehyde and acetaldehyde; 1,5-diphenyl-1,3,5-pentadienone (dibenzalacetone) from condensate from benzaldehyde and acetone; 2-(cyclo-1-hexenyl)cyclohexanone from cyclohexanone and isomerization; and 2-cyclohexylcyclohexanol from cyclohexanone and following reduction.

Claims

1. In the aldol condensation reaction wherein a ketone or aldehyde group having an alpha methylene group is reacted with a ketone or aldehyde group to form an alpha-, beta-unsaturated ketone or aldehyde, the improvement which comprises carrying out said reaction in the presence of a dialkyl boryl carboxylate of the formula:

R.sub.2.sup.V BOCOR.sup.IV

wherein

R.sup.iv is C.sub.1 -C.sub.6 hydrocarbon and

R.sup.v is each C.sub.1 -C.sub.4 alkyl.

2. Process according to claim 1, wherein the ketone or aldehyde group having an alpha methylene group is contained in a compound of the formula: ##STR6## and the other ketone or aldehyde group is contained in a compound of the formula:

R"COR' "

wherein:

R, r',r", and R'" is each hydrogen, alkyl, or aryl, and R and R' can be linked together to form a ring, and R" and R'" can be linked together to form a ring, and R' and R'" can be linked together, and R' and R" can be linked together.

3. Process according to claim 1, wherein the ketone or aldehyde group having an alpha methylene group is contained in a compound of the formula: ##STR7## and the other ketone or aldehyde group is contained in a compouund of the formula:

R"COR'"

wherein:

R, r',r", and R'" is each hydrogen, alkyl, or aryl, and R and R' can be linked together to form a ring, and R" and R'" can be linked together to form a ring.

4. Process according to claim 1, wherein the dialkyl boryl carboxylate is diethyl boryl pivalate.

5. Process according to claim 1, wherein the dialkyl boryl carboxylate is at least one of:

diethylboryl acetate

diethylboryl propionate

diethylboryl-cyclopropane carboxylate

diethylboryl benzoate

dipropylboryl pivalate

diethylboryl pivalate.

6. Process according to claim 1, wherein said temperature is 20.degree.-150.degree. C.

7. Process of claim 2, wherein the dialkyl boryl carboxylate is diethyl boryl pivalate.

8. Process of claim 6, wherein the dialkyl boryl carboxylate is diethyl boryl pivalate.