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

HRID 647371Notes

Reaction equation

S(Cl)(Cl)=O.O[C:6]1([C:18]([F:21])([F:20])[F:19])[C:15]2[C:10](=[C:11]([CH3:16])[CH:12]=[CH:13][CH:14]=2)[CH2:9][CH2:8][C:7]1=[O:17].C(OCC)(=O)C>CN(C)C1C=CN=CC=1.N1C=CC=CC=1.CCCCCC>[CH3:16][C:11]1[CH:12]=[CH:13][CH:14]=[C:15]2[C:10]=1[CH:9]=[CH:8][C:7]([OH:17])=[C:6]2[C:18]([F:19])([F:20])[F:21]

Participants

Conditions

Temperature: 25 °C

Procedure

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%.

Workup

additionThe reaction mixture was poured onto ice
extractionextracted with diethyl ether
extractionThe ether extract
washwas washed with water
dry with materiala saturated solution of NaHCO3 in water, dried (MgSO4)
concentrationconcentrated under reduced pressure

Sources & evidence

ORD record: ord-e5fca34784974191b50df60ee606ba7c
Source dataset: uspto-grants-1983_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04408077

Reaction notes

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