Hydrochloric Acid → HCID 178422345, compound

Participants

Reaction Steps

4-Acetyl-3-acetylthio-2-methylpyrazolo[1,5-a]benzimidazole (2.0 g, 6.97 mmole) was added to a mixture of concentrated hydrochloric acid (5 ml) and ethanol (30 ml) and refluxed for 5 hr. A yellow solid precipitated during the heating period and was filtered off after cooling, 0.9 g. This was a mixture of several components, none of them being the required product, and was discarded. The ethanolic solution was poured into a solution of sodium bicarbonate (excess) in water (300 ml) and the white solid filtered off, washed and dried, 0.7 g, 61%, mp. 250°-252° C. IR and TLC (+ Dox spray test) comparison with authentic (6) showed the samples to be identical.

Provenance & Evidence