Methanol → 2-Trifluoroacetyl-1-tetralone

Participants

Reaction Steps

A 250 mL one necked round bottomed flask equipped with a reflux condenser, nitrogen inlet and provisions for magnetic stirring was charged with ethyl trifluoroacetate (28.4 g, 0.2 mol) and 75 mL of ether. To this solution was added 48 mL of 25% sodium methoxide in methanol (0.21 mol). A solution of 1-tetralone (29.2 g, 0.2 mol) in 50 mL of ether was then added over about 5 min. The reaction mixture was then stirred at room temperature for 14h and then was diluted with 100 mL of 3N HCl. The phases were separated and the organic layer washed with 3N HCl, brine, dried over anhyd. MgSO4, filtered and concentrated in vacuo. The residue was then taken up in 70 mL of boiling ethanol/water and allowed to cool to room temperature whereupon crystals of 2-trifluoroacetyl-1-tetralone formed which were isolated by filtration and air dried to give 32 g, 81% of pure product with mp 48°-49° C. 1H NMR CDCl3 ε 2.8 (m, 2H), 2.9 (m, 2H), 7.2 (d, j=3.0 Hz, 1H), 7.3 6 (m, 1H), 7.50 (m, 1H), 7.98 (m, 1H); 19F NMR CDCl3 ε -72.0. EI GC-MS M+=242.

Provenance & Evidence