合成路线1

The reaction of 2,5-dimethoxybenzaldehyde (I) with ethyl acetoacetate (II) in a mixture of piperidine and glacial acetic acid in refluxing benzene gives ethyl alpha-acetyl-beta-(2,5-dimethoxyphenyl)acrylate (III), which is hydrogenated in a Parr low-pressure apparatus using 5% palladium on charcoal catalyst in ethyl acetate to yield ethyl alpha-acetyl-(2,5-dimethoxyphenyl)propionate (IV). The condensation of the propionate (IV) with 2,4.6-triaminopyrimidine in diphenylether at 195-230 C provides 2,4-diamino-7,8-dihydro-6-(2,5-dimethoxybenzyl)-5-methyl-7-oxopyrido[2,3-d]pyrimidine (VI). The key intermediate (VI) is converted to the 7-chloro compound (VII) by treatment with a 1:1 complex of N,N-dimethylformamide thionyl chloride, and finally (VII) is hydrogenolyzed with palladium on charcoal in the presence of potassium hydroxide to yield BW-301 U.