Methane, dichloromethoxy- → methyl 4-formyl-1H-pyrrole-2-carboxylate

To a solution of 2 (4.50 g, 36.0 mmol) in CH2Cl2:CH3NO2 (1:1, 40 mL) at −40° C., was added AlCl3 (12.48 g, 93.6 mmol) followed by α,α-dichloromethyl methyl ether (4.15 mL, 46.8 mmol). The resulting mixture was allowed to warm to room temperature and stirred for 16 hours. The reaction mixture was slowly poured onto ice (10.00 g) and allowed to warm to room temperature. The aqueous phase was extracted with CH2Cl2 (3×50 mL). The combined organic layer was dried over anhydrous MgSO4, filtered and concentrated to give 3 as a dark brown solid (3.40 g, 62%). 1H NMR (400 MHz, CDCl3) δ 10.32 (bs, 1H), 9.83 (s, 1H), 7.59 (d, J=1.6 Hz, 1H), 7.30 (s, 1H), and 3.88 (s, 3H); 13C NMR (100 MHz, CDCl3) δ 186.07, 161.71, 129.15, 127.71, 124.99, 114.56, and 52.34.

1. additionThe reaction mixture was slowly poured onto ice (10.00 g)
2. temperatureto warm to room temperature
3. extractionThe aqueous phase was extracted with CH2Cl2 (3×50 mL)
4. dry with materialThe combined organic layer was dried over anhydrous MgSO4
5. filtrationfiltered
6. concentrationconcentrated

ORD record

ord-3c85b1faf174478c846af6324e08e769

Source dataset

uspto-grants-2013_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08404728B2