Claims
- 1. A process for the preparation of a 6-substituted 2-(imidazolin-2-yl)-nicotinic acid of the formula III ##STR67## in which R.sub.2 is C.sub.1 -C.sub.4 -alkyl;
- R.sub.3 is C.sub.1 -C.sub.4 -alkyl or C.sub.3 -C.sub.6 -cycloalkyl; or
- R.sub.2 and R.sub.3, together with the carbon atom to which they are bonded, also represent a C.sub.3 -C.sub.6 -cycloalkyl radical which may be substituted by methyl radicals;
- X is hydrogen or methyl;
- Y is hydrogen; halogen; C.sub.1 -C.sub.6 -alkyl; C.sub.1 -C.sub.6 -haloalkyl; C.sub.1 -C.sub.6 -hydroxyalkyl; C.sub.1 -C.sub.6 -alkoxy; C.sub.1 -C.sub.6 -alkylthio; phenoxy; nitro; cyano; C.sub.1 -C.sub.4 -alkylamino; di-C.sub.1 -C.sub.4 -alkylamino; C.sub.1 -C.sub.4 -alkylsulphonyl; phenyl; halophenyl; lower alkylphenyl; lower alkoxyphenyl; C.sub.3 -C.sub.8 -alkenyloxy; C.sub.3 -C.sub.8 -haloalkenyloxy; C.sub.3 -C.sub.8 -alkynyloxy or C.sub.3 -C.sub.8 -haloalkynyloxy; and
- Z is a --CQ.sub.1 Q.sub.2 Q.sub.3 or --CQ.sub.1 Q.sub.4 Q.sub.5 radical in which
- Q.sub.1 is hydrogen or C.sub.1 -C.sub.4 -alkyl;
- Q.sub.2 is hydrogen or C.sub.1 -C.sub.4 -alkyl;
- Q.sub.3 is C.sub.1 -C.sub.6 -alkoxy that is unsubstituted or is substituted by C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -alkoxy, C.sub.4 -C.sub.9 -alkoxyalkoxy, cyano or by carbamoyl; phenoxy that is unsubstituted or is substituted by halogen, C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -alkoxy, C.sub.1 -C.sub.4 -haloalkyl or by nitro; or C.sub.3 -C.sub.6 -alkenyloxy or C.sub.3 -C.sub.6 -alkynyloxy;
- Q.sub.4 and Q.sub.5, together with the carbon atom to which they are bonded, represent C.sub.3 -C.sub.6 -cycloalkyl; or a 5- or 6-membered ring containing one oxygen atom or two oxygen atoms that are not vicinal, each of which radicals may be substituted by C.sub.1 -C.sub.4 -alkyl; or
- Z is a 5- or 6-membered, saturated or unsaturated, heterocyclic radical that is bonded by way of carbon and is unsubstituted or is substituted by lower alkyl;
- which consists in reacting a pyridine-2,3-dicarboxylic acid diester of the formula V ##STR68## in which X and Y are as defined above; R.sub.1 is hydrogen; the cation equivalent of an alkali metal, alkaline earth metal, magnesium, copper, iron, zinc, cobalt, lead, silver, nickel or quaternary ammonium or alkylammonium salt; C.sub.1 -C.sub.6 -alkyl unsubstituted or substituted by halogen, hydroxy, C.sub.1 -C.sub.3 -alkoxy, C.sub.3 -C.sub.6 -cycloalkyl, benzyloxy, furyl, phenyl, halophenyl, lower alkylphenyl, lower alkoxyphenyl, nitrophenyl, carboxy, C.sub.1 -C.sub.4 -alkoxycarbonyl or by cyano; C.sub.3 -C.sub.6 -cycloalkyl unsubstituted or mono- or di-substituted by C.sub.1 -C.sub.3 -alkyl; C.sub.3 -C.sub.6 -alkenyl unsubstituted or substituted by halogen, C.sub.1 -C.sub.3 -alkoxy, phenyl or by C.sub.1 -C.sub.4 -alkoxycarbonyl; or C.sub.3 -C.sub.6 -alkynyl unsubstituted or mono- or di-substituted by C.sub.1 -C.sub.3 -alkyl and
- R.sub.4 is a C.sub.1 -C.sub.3 alkyl radical; a C.sub.1 -C.sub.8 -alkylphenyl radical or a phenyl-C.sub.1 -C.sub.4 -alkyl radical; in aqueous solution at a temperature of between room temperature and the boiling point of the reaction mixture, under atmospheric pressure, in the presence of a catalytic amount of silver (II) ions and a peroxysulphate salt, with a carboxylic acid of the formula XVII
- Z--COOH (XVII),
- in which Z is as defined above,
- and reacting the resulting 6-substituted pyridine-2,3-dicarboxylic acid diester of the formula IV ##STR69## in an inert organic solvent, in the presence of a strong base at temperature of between room temperature and the boiling point of the reaction mixture under atomospheric pressure, with a 2-aminoalkanecarboxylic acid amide of formula XV ##STR70## in which R.sub.2 and R.sub.3 are as defined above, and the resulting salt of the 2-(imidazolin-2-yl)-nicotinic acid of formula III is taken up in aqueous acidic solution to form the free 6-substituted-2-(imidazolin-2-yl)-nicotinic acid of formula III.
- 2. A process of claim 1 in which R.sub.1 is hydrogen or C.sub.1 -C.sub.6 -alkyl; Y is hydrogen, C.sub.1 -C.sub.6 -alkyl or halogen; Z is a heterocyclic radical or, if it is --CQ.sub.1 Q.sub.2 Q.sub.2 Q.sub.3, is a C.sub.1 -C.sub.6 -alkoxy-C.sub.1 -C.sub.4 -alkyl-, phenoxy-C.sub.1 -C.sub.4 -alkyl or carbamoyl-C.sub.1 -C.sub.4 -alkoxy-C.sub.1 -C.sub.4 -alkyl radical or, if it is --CQ.sub.1 Q.sub.4 Q.sub.5, is a C.sub.3 -C.sub.6 -cycloalkyl radical or a C.sub.3 -C.sub.6 -cycloalkyl radical that may be substituted by C.sub.1 -C.sub.4 -alkyl.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2301/87 |
Jun 1987 |
CHX |
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Parent Case Info
This is a division of application Ser. No. 206,552, filed on June 14, 1988, now abandoned.
US Referenced Citations (7)
Foreign Referenced Citations (2)
Number |
Date |
Country |
0041623 |
May 1981 |
EPX |
0216360 |
Sep 1986 |
EPX |
Divisions (1)
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Number |
Date |
Country |
Parent |
206552 |
Jun 1988 |
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