Pyrrole-2-Carboxylic Acid → HCID 10931649, compound

Method 7 General Experimental: Pyrrole-2-carboxylic acid (27.0 mmol, 3.00 g) in CH2Cl2 (100 ml) was treated with oxalyl chloride (54.0 mmol, 4.70 ml) and DMF (1 drop), then heated to reflux for 1 h, then concentrated under reduced pressure. The residue was diluted with CH2Cl2 (100 ml) and pyridine (6.50 ml), and treated with O,N-dimethyl-hydroxylamine hydrochloride (27.0 mmol, 2.65 g), then held at room temperature overnight. The resulting solution was diluted with ethyl acetate (250 ml), washed with 10% aqueous citric acid (2×30 ml), saturated aqueous sodium bicarbonate (2×30 ml), then brine (2×30 ml). The organics were concentrated under reduced pressure. Purification of the residue by silica gel chromatography provided 3.42 g (82%) of 1H-pyrrole-2-carboxylic acid methoxy-methyl amide. 1H NMR (CDCl3) δ6.90-6.80 (1H, m), 6.79-6.60 (1H, m), 6.18 (1H, dd, J=3.7, 1.3), 3.81 (3H, s), 3.01 (3H, s).

1. temperatureheated
2. temperatureto reflux for 1 h
3. concentrationconcentrated under reduced pressure
4. additionThe residue was diluted with CH2Cl2 (100 ml) and pyridine (6.50 ml)
5. washwashed with 10% aqueous citric acid (2×30 ml), saturated aqueous sodium bicarbonate (2×30 ml)
6. concentrationThe organics were concentrated under reduced pressure
7. customPurification of the residue by silica gel chromatography

ORD record

ord-27ce4ec0bd3c493ea4353993446e2cb7

Source dataset

uspto-grants-2003_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06610730B2