Borohydride → HCID 178473725, compound

Participants

Reaction Steps

To a solution of Compound B (5.3 g, 11.7 mmol) in dichloromethane (100 mL) were added acetic acid (15 mL) and 4-formylimidazole (1.15 g, 12 mmol). After 10 min, sodium triacetoxyborohydride (2.54 g, 12 mmol) was added. After 3 hr, 4-formylimidazole (0.5 g, 5.8 mmol) and borohydride (1.2 g, 5.5 mmol) were added. After 18 hr, aldehyde (0.5 g) and borohydride (1.2 g) were added. After 5 hr, the mixture was concentrated. Aqueous ammonia (100 mL) and chloroform (100 mL) were added to the residue and the mixture was stirred vigorously for 0.5 hr. The two layers were separated and the organic layer was washed again with aqueous ammonia (100 mL). The combined aqueous layer was extracted with chloroform (100 mL), the two organic extracts were combined, dried (K2CO3), and concentrated. The residue was purified by flash silica gel column chromatography (step gradient of 5% and 10% MeOH in chloroform) to afford a solid which was dissolved in dichloromethane (50 mL) and HCl gas was bubbled through the solution. The mixture was concentrated in vacuo to afford a solid which was dissolved in water and lyophilized to afford Compound C (5.2 g, 73%). MS: (M+H)+ 532

Provenance & Evidence