摘要:
We report on the syntheses of some simply substituted 8-methylpyrido[2,3-d]pyrimidines (8-methyl-N5-deazapterins). We have found that purified triformyl methane condenses with 2-amino-6-(methylamino)pyrimidin-4(3H)-one (11) to give 6-formyl-N5-deazapterin (10a) in good yield. Alpha,-beta-Unsaturated carbonyl compounds and their protected forms, e.g., beta-halo acetals, also react with 11 in a Michael reaction to give 8-methyl-N5-deazapterins in good yield. Only one of the two possible isomeric products from reaction with the alpha,beta-unsaturated carbonyl compounds was observed.