Formamide → HCID 58906455, compound

Participants

Reaction Steps

A solution of 29.3 g (76 mmol) of (29a) in 400 ml formamide was heated for 2 h at 200° C. The solution turned from yellow to black. The reaction was monitored by 1H-NMR. After completed reaction the mixture was cooled to room temperature and poured into ice-water (800 g). The mixture was extracted with DCM (6×1 l). The combined organic layers were dried over Na2SO4 and concentrated in vacuo. The residue was dissolved in 1.2 l of methanol and 4.3 g (114 mmol) of sodiumborohydride were added portion wise. The mixture was stirred for 1 h at room temperature and another hour at 60° C. The reaction mixture was cooled to room temperature and quenched with 25 ml of water. The solvent was evaporated in vacuo. The residue was dissolved in 750 ml of ammonia and extracted with DCM (7×1.5 l). The combined organic layers were dried over Na2SO4 and concentrated in vacuo to give 24.8 g of crude product, which was purified by column chromatography (SiO2, heptane:EtOAc, 1:1→1:3). Trituration with Et2O of the eluated product yielded 3.44 g (8.6 mmol, 11.3% from compound (26)) of compound (30a) as a white solid.

Provenance & Evidence