Catalytic process for the preparation of thiazole derivatives

• Main Authors: Desponds, Olivier, Faber, Dominik, Gressly, Remy, Rapold, Thomas, Passafaro, Marco
• Format: Patent
• Language: English
• Published: 12.02.2004

There are described a process for the preparation of a compound of formula in free form or in salt form, wherein Q is CH or N; Y is NO 2 or CN; Z is CHR 3 , O, NR 3 or S; R 1 and R 2 are, for example, C 1 -C 8 alkyl or together form an alkylene bridge; R 3 is H or C 1 -C 1-2 alkyl which is unsubstituted or substituted by R 4 ; and R 4 is unsubstituted or substituted aryl or heteroaryl; wherein a) a compound of formula (II), wherein X is a leaving group, is reacted with a chlorinating agent to form a compound of formula (III), in free form or in salt form; and b) the compound of formula (III) thereby obtained is reacted with a compound of formula wherein R 1 , R 2 , Y, Z and Q are as defined for compound (I); in which process the chlorination according to process step a) is performed using a chlorinating agent in the presence of catalytic amounts of SO 2 ; a process for the preparation of a compound of formula (III) according to process a) hereinbefore; and the use of the compouds of formulae (II), (III) and (IV) in a process as described hereinbefore. 1