Trimethylsilyl cyanide → 6,7-Dihydrobenzo[b]thiophene-4-carbonitrile

To a suspension of zinc iodide (6.2 g) in acetonitrile (200 ml) were added 4-keto-4,5,6,7-tetrahydrothianaphthene (20 g) and trimethylsilylcyanide (18 ml) successively. The mixture was stirred at room temperature for 5 hours. The reaction mixture was concentrated. The residue was dissolved in pyridine (65 ml), followed by adding phosphryl chloride (15 ml) dropwise at room temperature. The mixture was refluxed for 30 minutes. The reaction mixture was cooled with ice and thereto was added dropwise isopropanol. The reaction mixture was poured onto ice water and extracted with ethyl acetate. The extract was washed by hydrochloric acid, water and a saturated aqueous solution of sodium chloride successively, dried over anhydrous magnesium sulfate and concentrated to give the title compound (17 g) having the following physical data.

1. concentrationThe reaction mixture was concentrated
2. dissolutionThe residue was dissolved in pyridine (65 ml)
3. additionby adding phosphryl chloride (15 ml) dropwise at room temperature
4. temperatureThe mixture was refluxed for 30 minutes
5. temperatureThe reaction mixture was cooled with ice
6. additionwas added dropwise isopropanol
7. additionThe reaction mixture was poured onto ice water
8. extractionextracted with ethyl acetate
9. washThe extract was washed by hydrochloric acid, water
10. dry with materiala saturated aqueous solution of sodium chloride successively, dried over anhydrous magnesium sulfate
11. concentrationconcentrated

ORD record

ord-a6384d1ce26e400dbf1c406fa64f33e0

Source dataset

uspto-grants-2002_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06420391B1