Patent ID: 7635782

Claim:
A method for the preparation of a compound of formula (I): wherein Z represents a C 1-6 -alkyl, C 2-6 -alkenyl, C 3-8 -cycloalkyl, aryl, heteroaryl, aryl C 1-6 -alkyl, or heteroaryl-C 1-6 -alkyl group, optionally substituted by one to three groups independently selected from the group consisting of halogen, C 1-6 -alkyl and C 1-6 -alkylthio, said method comprising: reacting a compound of formula (II): wherein X represents halogen, cyano, methanesulfonyloxy, p-toluenesulfonyloxy or trifluoromethanesulfonyloxy, with a compound of formula (IIIa) or (IIIb): wherein: L represents halogen, cyano, methanesulfonyloxy, p-toluenesulfonyloxy or trifluoromethanesulfonyloxy; and R 1 , R 2 and R 3 independently from each other represent hydrogen, C 1-6 -alkyl, C 2-6 -alkenyl, C 3-8 -cycloalkyl, C 4-8 -cycloalkenyl, (C 1-6 -alkyl)-C 3-8 -cycloalkyl, (C 1-6 -alkyl)-C 4-8 -cycloalkenyl, phenyl or (C 1-6 -alkyl)-phenyl, or R 2 and R 3 together form a 5-, 6- or 7-membered ring, then treating the obtained product with a thiocarboxylic acid of formula (IV) or a salt thereof: wherein Z is as defined above, and subsequently carrying out a nitration reaction.