Ammonia → HCID 136388364, compound

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.

1. concentrationThe reaction mixture was concentrated in vacuo
2. customto give a solid
3. customat 50° C. for 2 h to give a homogenous solution
4. customThe solvent was evaporated in vacuo
5. additiontreated with a saturated solution of NaHCO3 (50 mL)
6. filtrationThe precipitate was collected by filtration
7. washwashed with water (2×10 mL)
8. customdried in open air for 3 h
9. customThe precipitated material was recrystallized from methanol

ORD record

ord-2c0a8a83682149b5bc3747fb01d34ec1

Source dataset

uspto-grants-2003_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06653340B1