4-Hydroxy-2-methylpyrimidine-5-acetic

Hydroxy-2-methylpyrimidine-6-methylamine. A mixture of 100 g. of 4-hydroxy-2-methylpyrimidin 5-acetic ester and 135 cc. of 50% hydrazine hydrate is heated on a steam bath for two hours, during which time the ester dissolves and the hydrazide separates. The hydra-zide is filtered from the cooled solution and recrystallized from ethanol m.p. 246 yield, 80-85%. 

Pyrimidine derivatives can be prepared in two ways. The first is the condensation of ethyl a-n-butylacetoacetate with thiourea in methanol in the presence of sodium methylate, and the reaction of the intermediate product (21) with methyl iodide. The compound 5-n-butyl-2-methylthio-4-hydroxy-6-methylpyrimidine (22) is formed, the reaction of which with dimethylamine acetate gives dimethirimol, and with ethylamine acetate, ethirimol, with a yield of 80%. 

The pyrimidine part (4,5-dichloro-6-methylpyrimidine, 11) is synthesized in a two-step sequence starting with the condensation of 2-chloro-3-oxobutanoic acid methyl ester (8) and formamidine acetate 9 [15] to give 5-chloro-4-hydroxy-6-methylpyrimidine (10) in high yield, followed by the chlorination of the hydroxy group using standard synthesis methodology [15-18]. Synthesis of the sub-... 

Na-2-cyanopropionylcyanamide allowed to react several hrs. at room temp, with 4-6 molar equivalents HCI in acetic acid or acetone -> 6-amino-2-chloro-4-hydroxy-5-methylpyrimidine. Y 97%. F. e. s. T. Hirayama et al., Heterocycles 2, 451-461 (1974) Chem. Pharm. Bull. 24, 26 (1976). 

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