Ammonia → HCID 136388364, compound

Participants

Reaction Steps

2-Cyano-6-hydroxybenzothiazole, (White, E. H.; McCapra, F.; Field, G. F. The structures and synthesis of firefly luciferin. J. Am. Chem. Soc. 1963, 85, 337-342; 0.8 g, 4.54 mmol) was added to a cooled, saturated methanol-HCl solution (15 mL) and the mixture was stirred for 24 h at ambient temperature. The reaction mixture was concentrated in vacuo to give a solid. The solid was suspended in anhydrous methanol (40 mL) and gaseous NH3 was introduced into the mixture at ambient temperature for 1 h and then at 50° C. for 2 h to give a homogenous solution. The solvent was evaporated in vacuo, and the resulting brown solid was suspended in methanol (15 mL) and then treated with a saturated solution of NaHCO3 (50 mL). The precipitate was collected by filtration, washed with water (2×10 mL) and then dried in open air for 3 h. The solid (0.94 g) was suspended in 3 mL of methanol and then treated with methanesulfonic acid (0.45 g, 4.69 mmol). The precipitated material was recrystallized from methanol to give 0.75 g (57%) of 2-amidino-6-hydroxybenzothiazole methanesulfonate as a yellow solid, mp 276-278° C.

Provenance & Evidence