Oxalyl chloride → 4,5,6,7-Tetrahydro-benzo[b]thiophene-2-carbonyl chloride

Temperature

0 °C

4,5,6,7-Tetrahydro-benzo[b]thiophene-2-carboxylic acid (1.0 g, 5.50 mmol) is dissolved in dichloromethane [DCM] (25 mL) that contains 5 drops of N,N-dimethylformamide dimethylformamide [DMF] under nitrogen and cooled to 0° C. Oxalyl chloride (13.7 mL of a 2.0M solution in ACM) is added via syringe and, allowed to warm to RT over 1 hour. All solvent is then removed under reduced pressure, and the resultant oil is reduced from toluene (3×20 mL) to remove residual oxalyl chloride. The residue is then dissolved in ethyl acetate and washed with saturated sodium bicarbonate (1×100 mL), then washed with saturated sodium chloride (1×100 mL) and dried over sodium sulfate. The solution is then filtered and concentrated under reduced pressure to give 4,5,6,7-tetrahydro-benzo[b]thiophene-2-carbonyl chloride (8) as an off-white solid (1.03 g).

1. temperatureto warm to RT over 1 hour
2. customAll solvent is then removed under reduced pressure
3. customto remove residual oxalyl chloride
4. dissolutionThe residue is then dissolved in ethyl acetate
5. washwashed with saturated sodium bicarbonate (1×100 mL)
6. washwashed with saturated sodium chloride (1×100 mL)
7. dry with materialdried over sodium sulfate
8. filtrationThe solution is then filtered
9. concentrationconcentrated under reduced pressure

ORD record

ord-7e3449f1b0114adf835f25c7c6a279bf

Source dataset

uspto-grants-2012_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08247550B2