Carbon tetrabromide → HCID 89625010, compound

Participants

Reaction Steps

Perbromomethane (207 mg, 0.62 mmol) and DIPEA (131 μL, 0.75 mmol) were added successively to a solution of DMAP (3.05 mg, 0.03 mmol) and ethyl 5-(dimethylcarbamoyl)-3,4-dihydroxy-1-(4-methoxyphenyl)-1H-pyrrole-2-carboxylate (UL1-012) (87 mg, 0.25 mmol) in MeCN (3 mL) at −10° C. The reaction mixture was allowed to stir for 30 min and diethyl phosphite (166 μL, 0.75 mmol) added, the reaction was allowed to warm slowly to RT and stirred for 3 h. The reaction was quenched with 5% NaH2PO4 (aq.) (20 mL) and extracted with EtOAc (3×25 mL). The combined organics were washed with brine (50 mL), dried (MgSO4), filtered and concentrated in vacuo. The crude residue was purified by silica gel chromatography (40 g, 0-4% MeOH in DCM) to afford an orange oil. The compound was further purified by preparative HPLC (C-18 column, 21.2 mm i.d.×100 mm, 5 micron particle size, gradient 5-95% MeCN in 0.1% aq. formic acid over 16 min) to afford ethyl 3,4-bis((diethoxyphosphoryl)oxy)-5-(dimethylcarbamoyl)-1-(4-methoxyphenyl)-1H-pyrrole-2-carboxylate (UL1-092) (35 mg, 22%) as a yellow oil: m/z 621 (M+H)+ (ES+). 1H NMR (400 MHz, DMSO-d6) δ: 7.18-7.15 (m, 2H), 6.97-6.94 (m, 2H), 4.22-4.02 (m, 10H), 3.79 (s, 3H), 2.75 (s, 3H), 2.71 (s, 3H), 1.31-1.24 (m, 12H),1.07 (t, J=7.2 Hz, 3H).

Provenance & Evidence