Methyl iodide → Ethyl 1,2-dimethyl-1H-pyrrole-3-carboxylate

Temperature

0 °C

To a mixture of 2-methyl-1H-pyrrole-3-carboxylic acid ethyl ester (7.1 g, 46.05 mmol), iodomethane (5.73 mL, 92.1 mmol) in DMF (50 mL) at 0° C. was added sodium hydride (NaH) (2.39 g, 59.9 mmol, 60% in mineral oil) in one portion, the mixture was stirred at 0° C. for 1 h then the mixture was poured into ice-water (300 mL), extracted with EtOAc, the organic phase was washed with diluted HCl aqueous solution, water and saturated NaCl aqueous solution respectively; the EtOAc layer was then dried over anhydrous sodium sulfate, filtered, concentrated, the residue was purified with column to give a colorless oil, the desired title compound (3.25 g); 1H NMR (200 MHz, CDCl3): δ (ppm)=6.5-6.4 (m, 2H), 4.24 (q, 2H, J=7.1 Hz), 3.52 (s, 3H), 2.49 (s, 3H), 1.33 (t, 3H, J=7.1 Hz).

1. extractionextracted with EtOAc
2. washthe organic phase was washed with diluted HCl aqueous solution, water and saturated NaCl aqueous solution respectively
3. dry with materialthe EtOAc layer was then dried over anhydrous sodium sulfate
4. filtrationfiltered
5. concentrationconcentrated
6. customthe residue was purified with column
7. customto give a colorless oil

ORD record

ord-de5fa8f354244e5785950ce525ff8a1e

Source dataset

uspto-grants-2010_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07696223B2