Hydrochloric Acid → 4-Amino-6-methyl-2,5-dihydro-1,2,4-triazin-3-one

Participants

Reaction Conditions

Reaction Steps

A mixture of 17 g of 4-acetylamino-6-methyl-3-oxo-2,3,4,5-tetrahydro-1,2,4-triazine, 63 ml of hydrochloric acid (37%) and 250 ml of methanol is stirred for 4 hours at 50° C. After cooling to 15° C., 82 g of sodium acetate are added, the mixture is stirred for a further 15 minutes, and the solvent is removed by evaporation. The residue is taken up in 100 ml of ethanol, and the solvent is removed again in vacuo. The residue is taken up in 1200 ml of acetonitrile, undissolved salt precipitates are filtered off, the filtrate is evaporated to dryness, the residue is caused to crystallise by adding 50 ml of acetic acid ethyl ester at ambient temperature, and the crystals are filtered off and dried yielding 54.6 g (85% of the theoretical amount) of the title compound having a melting point of 113°-118° C.

Provenance & Evidence