Hydrogen Bromide → HCID 117642820, compound

Participants

Reaction Steps

HBr (33% in AcOH, 970 μL, 5.34 mmol) was added to a stirred solution of ethyl 3,4-bis(benzyloxy)-5-(dimethylcarbamoyl)-1-(4-methoxyphenyl)-1H-pyrrole-2-carboxylate (6) (2.82 g, 5.34 mmol) in AcOH (40 mL) and the reaction was allowed to stir for 16 h at RT. The reaction mixture was diluted with DCM (100 mL), washed with water (100 mL), brine (2×100 mL), the organic layer was dried (MgSO4), filtered and concentrated in vacuo. The residue was redissolved in AcOH (40 mL) and HBr (33% in AcOH, 970 μL, 5.34 mmol) was added dropwise and the reaction was allowed to stir at RT for 40 h. The reaction mixture was diluted with DCM (100 mL), washed with water (100 mL) and brine (2×100 mL). The organic layer was dried (MgSO4), filtered and concentrated in vacuo. The crude product was purified by silica gel chromatography (40 g, 0-30% EtOAc in toluene) to afford ethyl 4-(benzyloxy)-5-(dimethylcarbamoyl)-3-hydroxy-1-(4-methoxyphenyl)-1H-pyrrole-2-carboxylate (60) (1.48 g, 57%) as a colourless oil: m/z 439 (M+H)+ (ES+); 437 (M−H)− (ES−). 1H NMR (400 MHz, DMSO-d6) δ: 8.75 (s, 1H), 7.42-7.28 (m, 5H), 7.12-7.05 (m, 2H), 6.91-6.84 (m, 2H), 5.01 (s, 2H), 4.02 (q, J=7.1 Hz, 2H), 3.76 (s, 3H), 2.68 (s, 3H), 2.66 (s, 3H), 1.0 (t, J=7.1 Hz, 3H).

Provenance & Evidence