Hydrogen Sulfide → 2,4-Diamino-5-pyrimidinecarbothioamide

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Reaction Steps

Hydrogen sulfide is passed into a mixture of 2,4-diamino-5-pyrimidine carbonitrile (10.000 g., 0.0740 mole), triethylamine (10.3 ml., 0.0740 mole) and pyridine (6.0 ml., 0.074 mole) in dimethyl sulfoxide (100 ml.) for one-half hour. After storage at room temperature overnight, the brown solution is poured into water (500 ml.) with stirring. The product separates as a yellow crystalline solid which is collected by filtration, washed with water, dried at 56° C./0.1 mm. The yield of crude product melting at greater than 325° C. (uncorr.) is 12.020 g. (96.0%). Recrystallization of this material from 2-methoxyethanol affords the title compound as tan crystals melting above 350° C. (uncorr.) after drying at 110° C. at 0.1 mm.

Provenance & Evidence