Sodium Hydroxide → 2,5-Dichlorothiophene-3-carboxylic acid

Temperature

55 °C

A mixture of the 1-(2,5-dichloro-thiophen-3-yl)-ethanone (10 g, 51.26 mmol) and 9.5% NaOCl (150 mL, 230 mmol, 4.5 eq., commercial bleach) was treated with 5N NaOH (1 mL, 5 mmol, 0.1 eq.). The mixture was stirred vigorously and heated to 55° C. The internal temperature was monitored closely and heat was removed to control the exotherm. After 6 h at 61° C., starting material was completely consumed. The mixture was cooled to 0° C. and carefully quenched with 20% aq. NaHSO3 solution (20 mL). At 0° C., 6M HCl (12 mL) was added to adjust the pH to 1.5. The mixture was extracted with EtOAc (300 mL and 3×50 mL). The combined organic layers were washed with brine (200 mL), dried (Na2SO4), and concentrated to a white solid (8.8 g).

1. temperatureheat
2. customwas removed
3. customwas completely consumed
4. temperatureThe mixture was cooled to 0° C.
5. customcarefully quenched with 20% aq. NaHSO3 solution (20 mL)
6. additionAt 0° C., 6M HCl (12 mL) was added
7. extractionThe mixture was extracted with EtOAc (300 mL and 3×50 mL)
8. washThe combined organic layers were washed with brine (200 mL)
9. dry with materialdried (Na2SO4)
10. concentrationconcentrated to a white solid (8.8 g)

ORD record

ord-6abc54481ae84ec9b5c90a498d4726ca

Source dataset

uspto-grants-2007_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07282501B2