4-Bromothiophene-2-carbaldehyde → 4-Bromo-2-thiophenecarboxylic Acid

Temperature

0 °C

4-Bromothiophene-2-carbaldehyde (NN) (1.9 g, 10 mmol) was dissolved in 40 mL of t-BuOH and 4 mL of 2-methyl-2-butene. The reaction mixture was cooled to 0° C. and NaClO2 (1.1 g, 12 mmol) dissolved in 12 mL of 1M NaH2PO4 was added. The reaction mixture was let warm to room temperature and stirred for 5 hours. The reaction mixture was concentrated to about half the volume, and poured into 20 mL 1N NaOH and 50 mL Et2O. The aqueous layer was made acidic with 6N HCl and extracted with EtOAc. This organic layer was dried over sodium sulfate and concentrated to obtain the product (OO) as a white solid, 1.75 g, 8.5 mmol, 85% yield. 1H NMR 500 MHz (DMSO-d6) 8.02 (1H, s), 7.78 (1H, s).

1. additionwas added
2. temperatureThe reaction mixture was let warm to room temperature
3. concentrationThe reaction mixture was concentrated to about half the volume
4. additionpoured into 20 mL 1N NaOH and 50 mL Et2O
5. extractionextracted with EtOAc
6. dry with materialThis organic layer was dried over sodium sulfate
7. concentrationconcentrated
8. customto obtain the product (OO) as a white solid, 1.75 g, 8.5 mmol, 85% yield

ORD record

ord-a713fa3c099a46b7bb1b884d9d4f5738

Source dataset

uspto-grants-2014_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08921376B2