Ethanol → Methyl 4-(4-(tert-butoxycarbonylamino)phenyl)-1-methyl-1H-pyrrole-2-carboxylate

Participants

Reaction Conditions

Reaction Steps

A catalytic amount of tetrakis(triphenylphosphine)palladium, Pd(PPh3)4 (0.477 g, 0.413, 0.06 eq) was added to a solution of 4 (1.5 g, 6.88 mmol, 1 eq) and (4-((tert-butoxycarbonyl)amino)phenyl)boronic acid (1.57 g, 6.88 mmol, 1.20 eq) in a 9:3:1 combination (13.5 ml) of EtOH, toluene and water in the presence of K2CO3 (2.856 g, 3 eq.) in a 10-20 mL microwave vial containing a magnetic stirrer. The reaction vessel was flushed with nitrogen during each addition. The reaction mixture was sealed in an inert N2 atmosphere and heated with microwave radiation in an EMRYS™ Optimizer Microwave Station (Personal Chemistry) at 100° C. for 12 minutes. After LCMS and TLC analysis revealed completion of the reaction, the cooled reaction mixture was diluted with water (50 mL), extracted with EtOAc (3×40 mL), the filtrates combined, dried over MgSO4 and concentrated under vacuum. The resulting oil was subjected to flash chromatography (n-hexane/EtOAc 9:1) to give 5 (Yield—2.2 g, 97%). IR (FTIR, vmax/cm−): 3353, 2975, 1696, 1521, 1441, 1366, 1264, 1235, 1209, 1058, 822, 799, 657; 1H-NMR (400 MHz, CDCl3): δ 7.40 (d, 2H, J=8.8 Hz), 7.33 (d, 2H, J=8.8 Hz), 7.16 (d, 1H, J=2.0 Hz), 7.02 (d, 1H, J=2.0), 6.45 (br s, 1H), 3.95 (s, 3H), 3.83 (s, 3H), 1.52 (s, 9H); 13C-NMR (100 MHz, CDCl3): δ 161.7, 152.8, 136.5, 129.5, 125.9, 125.6, 123.7, 123.0, 119.0, 114.6, 80.5, 51.1, 36.9, 28.4; EIMS m/z (+EI) calc. for C18H22N2O4 (M)+ 330.38. found 330.46 (M+H)+.

Provenance & Evidence