Process for producing 4-trifluoromethylnicotinic acid

Abstract

A process for producing 4-trifluoromethylnicotinic acid of the formula (VIII) or its salt: ##STR1## which comprises (i) a first step of reacting a halide of the formula (I): CF.sub.3 COHal (I) wherein Hal is a halogen atom, with a compound of the formula (II): CH.sub.2 .dbd.CHOR.sup.1 (II) wherein R.sup.1 is an alkyl group, in the presence of a base to obtain a 4-alkoxy-1,1,1-trifluoro-3-buten-2-one of the formula (III): CF.sub.3 CO--CH.dbd.CH--OR.sup.1 (III) wherein R.sup.1 is as defined above, and reacting this compound with ammonia to obtain 4-amino-1,1,1-trifluoro-3-buten-2-one of the formula (IV): ##STR2## and (ii) a second step of subjecting the 4-amino-1,1,1-trifluoro-3-buten-2-one obtained in the first step and a compound of the formula (V): ACO.sub.2 R.sup.2 (V) wherein R.sup.2 is an ester-forming residue, and A is (R.sup.3 O)CH.dbd.CH-- or (R.sup.3 O).sub.2 CHCH.sub.2 --, wherein R.sup.3 is an alkyl group, to a condensation reaction to obtain a compound of the formula (VI) (inclusive of its salt): ##STR3## wherein R.sup.2 is as defined above, and/or a compound of the formula (VII) (inclusive of its salt): ##STR4## wherein R.sup.2 and R.sup.3 are as defined above, as the reaction product, and then subjecting the reaction product to ring closure and hydrolysis.

Dependencies are inferred from the claim text.