Patent ID: 8426586

Claim:
A process for preparing a compound of the formula (VII) wherein X denotes a methyne group or a nitrogen atom, R a denotes a benzyl, 1-phenylethyl or 3-chloro-4-fluorophenyl group and R 3 and R 4 denote a straight-chain or branched C 1-4 -alkyl group, comprising the following synthesis steps: a) reacting a compound of the formula (V) wherein X denotes a methyne group or a nitrogen atom and R a denotes a benzyl, 1-phenylethyl or 3-chloro-4-fluorophenyl group, in suitable solvents after corresponding activation with di-(C 1-4 -alkyl)-phosphonoacetic acid and b) reacting the resulting compound of the formula (VI) wherein X denotes a methyne group or a nitrogen atom, R a denotes a benzyl, 1-phenylethyl or 3-chloro-4-fluorophenyl group and R 1 denotes a straight-chain or branched C 1-4 -alkyl group, with the aldehyde of formula wherein R 3 and R 4 in each case represent a straight-chain or branched C 1 -C 4 -alkyl group, while the groups may be identical or different, or a corresponding aldehyde equivalent, using suitable organic or inorganic bases.