Phosphoric Acid → 6-Oxo-5,6,7,8-tetrahydronaphthalene-2-carbonitrile

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Reaction Conditions

Reaction Steps

A flame dried 1 liter round bottom flask with argon inlet, digital thermometer, and magnetic stir bar, was charged with a 68% NaCN/alumina mixture (21.22 g, 433 mmol)(NaCN and alumina were ground together in a morter and pestle according to the procedure of Dalton et al. J. Org. Chem., 44, (24) 4443(1979)), and tetrakis (triphenylphospine) palladium(0) (10.0 g, 8.65 mmol). The flask was purged three times via vacuum with argon and a solution of 6-bromo-2-tetralone (19.46 g, 86.5 mmol) in degassed toluene (400 mL) was added. The mixture was heated to 80° C. and stirred for 64 hrs at that temperature. Analysis by HPLC indicated 89% conversion (HPLC conditions, column: Waters C18 Bondapak, eluent: 80:20 (0.1% H3PO4 in H2O: CH3CN), flow: 2 mL/min, wavelength: 220 nm, Rt: bromotetralone =9.65 min, cyanotetralone=3.46 min). The reaction was cooled and the mixture filtered through silica gel (elution with 60% ethyl acetate in hexane.) Concentration of the appropriate fractions gave 9.4 g (68%) of 6-cyano-2-tetralone (98.7% by HPLC).

Provenance & Evidence