Methyl iodide → 1-Cyano-3-methylthio-4-oxo-5,6,7,8-tetrahydro-4H-cyclohepta[c]thiophene

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Reaction Conditions

Reaction Steps

Cycloheptan-1,3-dione (0.5 g, 4 mmol) was dissolved in DMF (10 mL) and cooled to 0° C. Sodium hydride (0.48 g of 60% dispersion in oil, 12 mmol) was added and the suspension stirred at 0-5° C. for 30 min. Carbon disulphide (0.45 g, 6 mmol) was added in one portion and the solution was stirred at 0-5° C. for 30 min. Methyl iodide (0.66 g, 4.4 mmol) was added in one portion and the mixture stirred at room temperature for 30 min. After cooling to 0-5° C., bromoacetonitrile (0.27 mL, 4.4 mmol) was added in one portion and the mixture was stirred at room temperature for 30 min. The mixture was then poured into water, extracted with ethyl acetate and the extracts dried (Na2SO4). After evaporating to dryness, the residue was purified by chromatographed on silica gel, eluting with ethyl acetate:hexane (1:4) to yield the title compound as a pale yellow solid (280 mg, 32%). 1HNMR (360 MHz, CDCl3) δ 1.88-1.96 (4H, m), 2.60 (3H, s), 2.75-2.78 (2H, m), 3.21-3.24 (2H, m). MS (ES+) 296 (M+1).

Provenance & Evidence