Diisopropylamine → 5-Bromo-2-chlorobenzo[b]thiophene

Temperature

-20 °C

n-Butyl lithium (0.64 ml, 1.2 mmol) was added drop wise to a solution of diisopropyl amine (0.25 mL, 1.5 mmol) in dry THF at −78° C. under nitrogen atmosphere over a period of 5 minutes. The reaction mixture was stirred at −20° C. for 30 minutes. To this was added 5-bromo-benzo[b]thiophene (200 mg, 0.938 mmol) in dry THF at −78° C., continued stirring for a further 30 minutes at −78° C., followed by the addition of N-chlorosuccinamide (225 mg, 1.68 mmol) in dry THF at −78° C. The resulting mixture was stirred at room temperature for 2 hours. The reaction was monitored by TLC (100% hexane). The reaction mixture was partitioned between ethyl acetate and saturated ammonium chloride. The organic layer was dried over sodium sulfate and concentrated to afford the crude product. Purification by column chromatography on silica gel (100% hexane) afforded 70 mg of the product (30% yield).

1. stirringcontinued stirring for a further 30 minutes at −78° C.
2. stirringThe resulting mixture was stirred at room temperature for 2 hours
3. customThe reaction mixture was partitioned between ethyl acetate and saturated ammonium chloride
4. dry with materialThe organic layer was dried over sodium sulfate
5. concentrationconcentrated
6. customto afford the crude product
7. customPurification by column chromatography on silica gel (100% hexane)

ORD record

ord-3ec49e29adc9421a8d966f6549417200

Source dataset

uspto-grants-2016_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09339501B2