1,2-Dichloroethane → tert-Butyl 2-(2-carbamoyl-1H-pyrrol-1-ylamino)-2-oxoethylcarbamate

Participants

Reaction Steps

1-Amino-1H-pyrrole-2-carboxamide (5.00 g, 40.0 mmol) and 2-(tert-butoxycarbonylamino)acetic acid (7.70 g, 44.0 mmol) were combined and dissolved in THF (250 mL). To this solution was added EDC (8.43 g, 44.0 mmol). The reaction was stirred at room temperature for 16 h, after which the reaction was concentrated in vacuo. The residue was partitioned between EtOAc (250 mL) and water (200 mL). The layers were separated, and the aqueous layer was extracted with EtOAc (150 mL). The combined organics were dried (MgSO4) and filtered. The filtrate was treated with activated charcoal and filtered over Celite. The filtrate was concentrated in vacuo to remove most of the solvent, then diluted with hexanes to ˜1 L. A solid was filtered off and dried to give 21A (8.73 g). The aqueous layer was extracted again with EtOAc (2×100 mL). A second crop was obtained similarly to above to give 465 mg, for a total yield of 9.20 g (82%). 21A had an analytical HPLC retention time=1.75 min (Phenomonex-Luna (4.6×50 mm S10); 10-90% MeOH/H2O (0.1% TFA) over 4 min; flow=4 mL/min) and a LC/MS M+-Boc+1=183.

Provenance & Evidence