Hydrochloric Acid → 4-methyl-5-(pyridin-4-yl)-4H-1,2,4-triazole-3-thiol

Participants

Reaction Conditions

Reaction Steps

To a mechanically stirred suspension of 2-isonicotinoyl-N-methylhydrazinecarbothioamide (610 g) in water (5.0 L) was added sodium bicarbonate (390 g) at r.t. The reaction mixture was thereafter slowly heated to 70° C. over 2 h, and maintained at that temperature for another 3.5 h before cooling (ice-bath) to 17° C., followed by adjusting the pH to 3 by slow addition (over 90 min) of concentrated hydrochloric acid (ca. 470 mL). Subsequent filtration of the reaction mixture, followed by washing the collected solid with dilute hydrochloric acid (0.1 N, 2×1.0 L), gave a wet cake that was dried at 100 mbar under a gentle stream of air for 1.5 days to yield 544 g of the title compound.

Provenance & Evidence