Abstract Thiamine hydrochloride (1a; 3-[(4-amino-2-methylpyrimidin-5-yl) methyl]-5-(2- hydroxyethyl)-4-methylthia-zolium chloride hydrochloride; vitamin B 1) has been synthesized in excellent yield by condensation of 3-mercapto-4-oxopentyl acetate (5a) with 3, 4-dihydro-7-methylpyrimido [4, 5-d] pyrimidine (4) in formic acid. The two intermediates 5a and 4 are prepared from 3-chloro-4-oxopentyl acetate (3) and 4-amino-2-methyl-5-( ...
![Pyrimido[4,5-D]pyrimidine, 1,5-dihydro-2-methyl- (6ci,8ci,9ci) Structure](https://image.chemsrc.com/caspic/367/31375-19-6.png)
