1958 年 78 巻 6 号 p. 647-651
Reëxaminations were made on the reaction of acetamidine with cis- and trans-2-alkoxymethylene-3-alkoxypropionitrile, 2-dialkoxymethyl-acrylonitrile, or 2-dialkoxymethyl-3-alkoxypropionitrile. It was thereby found that this reaction with 2-alkoxymethylene-3-alkoxypropionitrile in ethanol affords 2-methyl-4-amino-5-alkoxymethylpyrimidine while other two substances afforded 2-methyl-4-amino-5-acetamidomethylpyrimidine via 2, 7-dimethyl-5, 6-dihydropyrimido [4, 5-d] pyrimidine. The same 2-methyl-4-amino-5-acetamidomethylpyrimidine is obtained by the reaction of 2-alkoxymethylene-3-alkoxypropionitrile in methanol or in the presence of sodium ethoxide. This reaction course was followed by ultraviolet absorption spectrum and it was revealed through this means that acetalization occurred first by the action of the alcohol on 2-alkoxymethylene-3-alkoxypropionitrile and this was followed by cyclization to a pyrimidine ring.