Imidazole → HCID 86603582, compound

Participants

Reaction Steps

A 4-Hydroxy-L-proline derivative, methyl (4R)-2-(4-cyanobenzyl)-1-[(3,5-dichlorophenyl)acetyl]-4-hydroxypyrrolidine-2-carboxylate 21 (10 mmol) and imidazole (1.5 g, 22.5 mmol) were suspended in DMF (25 mL) and treated with tert-butyl(dimethyl)silyl chloride (1.6 g, 10.5 mmol). The reaction was stirred for 20 h, poured into water (100 mL) and extracted with diethyl ether (Et2O) (4×30 mL). The organic extracts were combined and washed with 1N HCl aq. (2×30 mL), water (1×50 mL), sat. aqueous NaHCO3 solution (1×30 mL) and sat. aq. NaCl solution (1×30 mL). The organic layer was dried (MgSO4) and solvent removed in vacuo to give methyl (4R)-4-{[tert-butyl(dimethyl)silyl]oxy}-2-(4-cyanobenzyl)-1-[(3,5-dichlorophenyl)acetyl]pyrrolidine-2-carboxylate (23) (˜5 g, 90%), which was used as such in subsequent reaction without further purification, LCMS, (m/z) 561 (M++H).

Provenance & Evidence