申请人:ISHIHARA SANGYO KAISHA, LTD.
公开号:EP0744400A2
公开(公告)日:1996-11-27
A process for producing 4-trifluoromethylnicotinic acid of the formula (VIII) or its salt:
which comprises (i) a first step of reacting a halide of the formula (I):
CF3COHal (I)
wherein Hal is a halogen atom, with a compound of the formula (II):
CH2=CHOR1 (II)
wherein R1 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):
CF3CO-CH=CH-OR1 (III)
wherein R1 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):
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):
ACO2R2 (V)
wherein R2 is an ester-forming residue, and A is (R3O)CH=CH- or (R3O)2CHCH2-, wherein R3 is an alkyl group, to a condensation reaction to obtain a compound of the formula (VI) (inclusive of its salt):
wherein R2 is as defined above, and/or a compound of the formula (VII) (inclusive of its salt):
wherein R2 and R3 are as defined above, as the reaction product, and then subjecting the reaction product to ring closure and hydrolysis.
一种生产式(VIII)的 4-三氟甲基烟酸或其盐的工艺:
其中包括 (i) 第一步:使式 (I) 的卤化物发生反应:
CF3COHal (I)
其中 Hal 是卤素原子,与式 (II) 的化合物反应:
CH2=CHOR1 (II)
其中 R1 为烷基,在碱存在下,得到式 (III) 的 4-烷氧基-1,1,1-三氟-3-丁烯-2-酮:
CF3CO-CH=CH-OR1 (III)
其中 R1 如上定义,将该化合物与氨反应,得到式(IV)的 4-氨基-1,1,1-三氟-3-丁烯-2-酮:
和 (ii) 第二步,将第一步得到的 4-氨基-1,1,1-三氟-3-丁烯-2-酮与式 (V) 化合物反应:
ACO2R2 (V)
其中 R2 为酯形成残基,A 为 (R3O)CH=CH- 或 (R3O)2CHCH2-,其中 R3 为烷基,通过缩合反应得到式 (VI) 化合物(包括其盐):
其中 R2 如上定义,和/或式(VII)化合物(包括其盐):
其中 R2 和 R3 如上文所定义,作为反应产物,然后将反应产物进行闭环和水解。