Ethyl Acetate → 5-Methyl-1-(trifluoromethyl)naphthalen-2-ol

Participants

Reaction Conditions

Reaction Steps

Thionyl chloride (0.33 mL, 4.52 mmol) was added dropwise at about 5° C. to a stirred solution of 3,4-dihydro-1-hydroxy-5-methyl-1-(trifluoromethyl)-2(1H)-naphthalenone (1.04 g, 4.26 mmol) and 4-(dimethylamino)pyridine (3.5 mg) in pyridine (0.73 mL) under dry nitrogen. The reaction mixture was stirred and allowed to warm slowly to 25° C. (about 45 min). The reaction was judged to be complete by tlc using silica gel thin layer plates and 20% (v/v) ethyl acetate in hexane as the mobile phase. The reaction mixture was poured onto ice and extracted with diethyl ether. The ether extract was washed with water and a saturated solution of NaHCO3 in water, dried (MgSO4) and concentrated under reduced pressure to give the title compound (961 mg, 100% yield). A small sample, purified by sublimation (30°-34° C., 0.05 mm), had mp 83°-84° C.; nmr (CDCl3) δ 2.65 (s, 3H), 7.1 (d, J=9 Hz, 1H), 7.25 (m, 1H), 7.35 (q, J=8 Hz, 1H), 7.85 (m, 1H), 8.05 (d, J=9 Hz, 1H); uvλmax (MeOH) 335 nm (ε2,770), 322 (2,420), 293 (4,050), 281 (4,680), 222 (46,400); Anal Calcd for C12H9F3O: C, 63.72% H, 4.01%; Found: C, 63.47% H, 3.96%.

Provenance & Evidence