Synthesis of 2-Mercapto- and 2-Methylthio- Dihydropyrimidine Derivatives by Biguinelli Type Reaction

Abstract

The preparation of 6-~2,2-dimethyl-1,3-dioxo1aa-4-yll-4-methyl--5-methoxycarbonyl-Z-thi0-1,2,3~6-t6ttthydpyriidie (1) and 6-(2.2-dimethyl-1,3-dioxolan-U-yl)-4-methyl-2-methylthio-5-methoxycarbo~~yl-1.6-dihydrapyrimidine(6) by Biguinelli type reaction is described.The products resulting from the acidic hydrolysis are studied.Previous papers report the synthesis of tetrahydrapyrimidines with a sugar moiety in positiorl 6, by the Biguinelli type reaction, starting from the sugar derivative, with urea and ethyl or 1 methyl acetoacetate .In this work the previous reaction is employed but with thiourea or Smethylthiourea in place of urea.when the 2.3-0-isopropylidene-0-glyceraldahydewas made to rract with methyl acetoacetate and thiourea, or S-methylthiourea, the following pyrimidine derivatives were obtained: 6-(2.2-dlmethyl-1,3-dionolan-4-yl)-4-methyl-5-methoxycaabonyl-2-thio-l,2,3,6-tetrahydropyrlmidine ( A ) ; and 6-(2,2d i n e t h y l -1 .3 -d i o x o l a a -U -y 1 l -4 -m e t h y l -2 -m e t h y l t h i -5 -e t h y c r b n y l -l , G -d i h y d p y i d i n