Dimethylformamide → diethyl 1-amino-1H-pyrrole-2,5-dicarboxylate

NaH (60% in mineral oil, 154.3 mg, 3.86 mmol) was rinsed with hexanes (5 ml), then anhydrous DMF (10 ml) was added, to this suspension 406B (0.68 g, 3.22 mmol) was added portionwise at 0° C., and the mixture was stirred for 1 h from 0° C. to rt. O-(2,4-dinitro-phenyl)-hydroxylamine (705.6 mg, 3.54 mmol) was added in two portions at 0° C., the reaction mixture was stirred at rt overnight. Water (50 ml) was added, the mixture was extracted with EtOAc (3×25 ml), the combined organic layer was washed with water (4×20 ml) and brine (1×20 ml), dried and concentrated. The residue was purified by silica gel flash column chromatography to give 406C (480 mg, 66%) as a yellow solid (25% EtOAc—hexanes).

1. additionwas added portionwise at 0° C.
2. stirringthe reaction mixture was stirred at rt overnight
3. extractionthe mixture was extracted with EtOAc (3×25 ml)
4. washthe combined organic layer was washed with water (4×20 ml) and brine (1×20 ml)
5. customdried
6. concentrationconcentrated
7. customThe residue was purified by silica gel flash column chromatography

ORD record

ord-7680834a6c9146efa1f6ae350a90ab96

Source dataset

uspto-grants-2006_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07030112B2