Hydrogen Bromide → HCID 178419273, compound

Participants

Reaction Steps

The hydrochloride salt from Example VIII, above (0.247 g, 0.438 mmol), was treated with 3 ml of 32% hydrogen bromide in acetic acid for 75 min at room temperature. Addition of 70 ml ether gave crude 7-(L-arginamido)-3-phenylcoumarin dihydrobromide that was precipitated twice from methanol/ether yielding 0.221 g (91%) of an off white powder: mp 168°; TLC (SiO2 : ethyl acetate/2-butanone/formic acid/water-5:3:1:1) Rf=0.30. This material, without further purification, was dissolved in 4 ml of dry pyridine containing 0.11 ml (0.80 ml) of triethylamine and 0.436 g (1.99 mmol) of N-benzoyloxy-succinimide. The reaction proceeded overnight at room temperature. The pyridine was removed in vacuo and the crude product was purified by preparative layer chromatography on silica gel with several developments in ethyl acetate/formic acid/water (32:1:1). The purified material was taken up in 1000 ml ethyl acetate/1-butanol (1:1) and washed with 200 ml volumes of N HCI, brine (3x), and water (2x). The organic layer was evaporated in vacuo yielding 0.139 g (65.4%) of II as the hydrochloride salt: mp 251°; TLC (SiO2 : ethyl acetate/2-butanone/formic acid/water-5:3:1:1) Rf=0.67.

Provenance & Evidence