2-Bromopropane → HCID 89610400, compound

Participants

Reaction Conditions

Reaction Steps

To a stirred suspension of triethylammonium 3,4-bis(benzyloxy)-5-(dimethylcarbamoyl)-1-(4-methoxyphenyl)-1H-pyrrole-2-carboxylate (7) [prepared as example B-step (iv) using ethyl 3,4-bis(benzyloxy)-5-(dimethylcarbamoyl)-1-(4-methoxyphenyl)-1H-pyrrole-2-carboxylate (6) as starting material] (360 mg, 0.60 mmol) and Cs2CO3 (429 mg, 1.32 mmol) in DMF (3 mL) was added 2-bromopropane (197 μL, 2.10 mmol) and the reaction stirred at 40° C. for 2 h then partitioned between EtOAc (50 mL) and water (20 mL). The organic was separated and washed with water (2×50 mL), brine (2×50 mL), dried (MgSO4), filtered and concentrated in vacuo to afford a yellow oil. The residue was purified by silica gel chromatography (40 g, 20-60% EtOAc in isohexane) to afford isopropyl 3,4-bis(benzyloxy)-5-(dimethylcarbamoyl)-1-(4-methoxyphenyl)-1H-pyrrole-2-carboxylate (8) (108 mg, 33%) as a yellow oil: 1H NMR (400 MHz, DMSO-d6) δ: 7.51-7.43 (m, 2H), 7.43-7.28 (m, 8H), 7.19-7.05 (m, 2 H), 6.96-6.84 (m, 2H), 5.13 (s, 2H), 4.96 (s, 2H), 4.85 (sept., J=6.2 Hz, 1H), 3.78 (s, 3H), 2.72 (s, 3H), 2.71 (s, 3H), 1.10 (d, J=6.2 Hz, 6H).

Provenance & Evidence