Sodium Hydroxide → 4-(4-((tert-Butoxycarbonyl)amino)-1-methyl-1H-pyrrole-2-carboxamido)-1-methyl-1H-pyrrole-2-carboxylic acid

Participants

Reaction Steps

A stirred solution of Boc pyrrole dimer (3) (0.805 g, 2.1 mmol) in MeOH (40 mL) was treated with 1M NaOH solution (25 mL). The reaction mixture was stirred at room temperature for 18 hours. The volume was reduced in vacuo and the aqueous solution extracted with EtOAc (50 mL). The solvent was removed from the EtOAc fraction and the residue was treated with 1M NaOH solution (10 mL) for a further 3 hours. This was combined with the previous aqueous fraction and acidified to pH2-3 with 1M HCl solution and the suspension extracted with EtOAc (3×75 mL). The organic fractions were combined, dried over MgSO4 and concentrated in vacuo to give a yellow foam 0.781 g (100%). 1H NMR d6-DMSO δ 12.07 (1H, bs, OH), 9.81 (1H, s, N—H), 9.08 (1H, s, N—H), 7.40 (1H, d, J=1.9 Hz, Py-H), 6.88 (1H, s, Py-H), 6.84 (1H, s, Py-H), 6.83 (1H, s, Py-H), 3.81 (3H, s, N—CH3), 3.80 (3H, s, N—CH3), 1.45 (9H, s, Boc-H); 13C NMR d6-DMSO δ 171.9, 161.9, 158.3, 152.8, 122.6, 122.3, 120.2 (CH), 119.4, 117.0 (CH), 108.3 (CH), 103.7 (CH), 78.3, 36.1 (CH3), 36.1 (CH3), 28.1 ([CH3]3).

Provenance & Evidence