Trifluoroacetic acid → Methyl 3-phenyl-1H-pyrrole-2-carboxylate

Temperature

0 °C

1-tert-Butyl 2-methyl 3-phenyl-1H-pyrrole-1,2-dicarboxylate (18.0 g, 59.7 mmol) was dissolved in CH2Cl2 (20 mL) and cooled to 0° C. TFA (23.0 mL, 0.299 mmol) was added to the reaction mixture and the solution stirred at room temperature for 14 h. The reaction mixture was concentrated under reduced pressure to remove excess of TFA. To the resulting residue was added 10% sodium bicarbonate solution (50 mL) and the aqueous portion extracted with CH2Cl2. The organic layer was separated, dried over sodium sulfate, filtered and concentrated under reduced pressure. The residue was purified by column chromatography using CombiFlash (REDISEP®, silica gel, 40 g, 30% EtOAc/hexanes) to obtain methyl 3-phenyl-1H-pyrrole-2-carboxylate (7.50 g, 62.4%). 1H NMR (400 MHz, DMSO-d6) δ ppm 3.69 (s, 3H), 6.29 (t, J=2.8 Hz, 1H), 7.02 (d, J=2.8 Hz, 1H), 7.03 (m, 5H), 12.0 (s, 1H).

1. concentrationThe reaction mixture was concentrated under reduced pressure
2. customto remove excess of TFA
3. additionTo the resulting residue was added 10% sodium bicarbonate solution (50 mL)
4. extractionthe aqueous portion extracted with CH2Cl2
5. customThe organic layer was separated
6. dry with materialdried over sodium sulfate
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure
9. customThe residue was purified by column chromatography

ORD record

ord-a2c25b43bb28463ca416ed9c76ddf72a

Source dataset

uspto-grants-2015_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09050345B2