Hydrochloric Acid → Megazol

Participants

Reaction Steps

1-(1-Methyl-5-nitro-2-imidazolecarboximidoyl)-3-thiosemicarbazide is cyclized as in Example 10 with the exception that the 0.3 g. of the thiosemicarbazide in 7 ml. of 6N hydrochloric acid is replaced by 0.49 g. of the thiosemicarbazide in 5 ml. of methanol plus 0.5 ml. of concentrated hydrochloric acid. The cyclization is also effected by the use of 0.49 g. of the thiosemicarbazide in 5 ml. of methanol plus 0.5 ml. of 6N ethanolic hydrogen chloride. In each of these variations, a 78% yield of the title compound is realized. The cyclization is likewise accomplished by the use of dilute aqueous sulfuric acid, phosphoric, nitric, p-toluenesulfonic, benzene sulfonic, methylsulfonic or hydrobromic acid.

Provenance & Evidence