Methyl 6-(2,2-dimethylpropionylamino)-2-nitro-3-(2-oxopyrrolidin-1-yl)-benzoate → methyl 6-(2,2-dimethylpropionylamino)-2,3-dihydro-1H-benzo[d]pyrrolo[1,2-a]imidazole-5-carboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture of methyl 6-(2,2-dimethylpropionylamino)-2-nitro-3-(2-oxopyrrolidin-1-yl)-benzoate (Intermediate 57, 0.89 g), and iron powder (1.37 g) in acetic acid (25 mL) was stirred and heated at 115° C. for 2.5 hours. After cooling, the mixture was concentrated in vacuo and the residue was dissolved in ethyl acetate and 2M sodium hydroxide solution and filtered through celite. The organic phase was dried (Na2SO4) and filtered. The filtrate was concentrated in vacuo and the residue was purified by chromatography on silica, eluting with a mixture of ethyl acetate and cyclohexane with a gradient of 50-100%. The product was repurified by chromatography on silica, eluting with a mixture of methanol and ethyl acetate with a gradient of 0-10% to give methyl 6-(2,2-dimethylpropionylamino)-2,3-dihydro-1H-benzo[d]pyrrolo[1,2-a]imidazole-5-carboxylate (0.616 g) as an off-white solid.

Provenance & Evidence