Acetylenes. Part 2. 2-methylpyrimidin-4(3H)-ones and 4-amino-6-(1-hydroxyalkyl)-2-methylpyrimidines from alka-2,3-dienoates and 4-hydroxyalk-2-ynenitriles, respectively☆

Abstract Ethyl alka-2,3-dienoates and 4-tetrahydropyranyloxyalk-2-ynenitriles provide a 3-atom fragment when reacted with acetamidine in tetrahydrofuran, to furnish 2-methylpyrimidin-4(3H)-ones and 4-amino-2-methyl-6-(1-tetrahydropyranyloxyalkyl)pyrimidines, respectively (60 – 70% yield). The latter, with hydrochloric acid / ethanol, gave the corresponding 4-amino-6-(1-hydroxyalkyl-2-methylpyrimidines as their hydrochloride salts.