Methyl pyrrole-2-carboxylate → methyl 1-{2-[4-(difluoromethoxy)phenyl]-2-oxoethyl)-1H-pyrrole-2-carboxylate

Potassium tert-butoxide (430 mg, 3.82 mmol) was added to a solution of methyl 1H-pyrrole-2-carboxylate (435 mg, 3.48 mmol), and 2-bromo-1-[4-(difluoromethoxy)phenyl]ethanone (1.01 g, 3.82 mmol) in DMF (7.5 mL) at 0° C., the resulting red suspension was stirred from 0° C. to room temperature for 18 h. The reaction mixture was diluted with EtOAc (30 mL) and water (10 mL). The organic layers were then separated and washed with further water (10 mL), dried (MgSO4) filtered and concentrated in vacuo to give an orange residue. The residue was purified by flash column chromatography (Biotage SP4, 40 g cartridge, 10%-20% EtOAc gradient in n-hexanes) to give methyl 1-{2-[4-(difluoromethoxy)phenyl]-2-oxoethyl}-1H-pyrrole-2-carboxylate as a yellow gum, (417 mg, yield 38%). 1H NMR (400 MHz, CDCl3): δ 3.69 (s, 3H), 5.69 (s, 2H), 6.23 (dd, 1H, J 4.0, 2.6 Hz), 6.60 (t, 1H, J 73.0 Hz), 6.82 (dd, 1H, J 2.5, 1.9 Hz), 7.03 (dd, 1H, J 4.0, 1.8 Hz), 7.19 (d, 2H, J 8.8 Hz), 7.97-8.03 (m, 2H).

1. customThe organic layers were then separated
2. washwashed with further water (10 mL)
3. dry with materialdried (MgSO4)
4. filtrationfiltered
5. concentrationconcentrated in vacuo
6. customto give an orange residue
7. customThe residue was purified by flash column chromatography (Biotage SP4, 40 g cartridge, 10%-20% EtOAc gradient in n-hexanes)

ORD record

ord-d7457b60db9542ce89885d8c906c0a52

Source dataset

uspto-grants-2013_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08604034B2