反应详情

As shown hereinbelow in Example 1, the intermediate 4-(2-fluorophenyl)-2,6-dimethyl-3,5-pyridinedicarboxylic acid was prepared in very good yield by first adding concentrated aqueous ammonia to a mixture of 2-fluorobenzaldehyde and methyl acetoacetate in methanol to produce dimethyl 4-(2-fluorophenyl)-1,4-dihyro-2,6-dimethyl-3,5-pyridinedicarboxylate, oxidizing the 1,4-dihydro compound with 4N nitric acid to produce dimethyl 4-(2-fluorophenyl)-2,6-dimethyl-3,5-pyridinedicarboxylate and saponifying the latter ester by heating it with sodium hydroxide in aqueous methanol at about 60°-65° C. to produce 4-(2-fluorophenyl)-2,6-dimethyl-3,5-pyridinedicarboxylic acid.

1. customin very good yield