Sulfuric Acid → 3,4-dihydro-1-hydroxy-5-methyl-1-(trifluoromethyl)-2(1H)-naphthalenone oxime

HRID 615517Notes

Reaction equation

OS(O)(=O)=O.[F:6][C:7]([F:23])([F:22])[C:8](=[O:21])[C:9](=[N:19][OH:20])[CH2:10][CH2:11][C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][C:13]=1[CH3:18]>C1(C)C=CC=CC=1>[OH:21][C:8]1([C:7]([F:22])([F:23])[F:6])[C:17]2[C:12](=[C:13]([CH3:18])[CH:14]=[CH:15][CH:16]=2)[CH2:11][CH2:10][C:9]1=[N:19][OH:20]

Participants

Conditions

Temperature: 25 °C

Procedure

Cold concentrated H2SO4 (12 ml, 98% w/v H2SO4 in water) was added to a stirred suspension of 1,1,1-trifluoro-5-(2-methylphenyl)-2,3-pentanedione 3-oxime (11.9 g, 45.9 mmol) in toluene (16 mL) at 0° C. The reaction mixture and allowed to warm to room temperature (25° C.) and then stirred for 30 min. Ice was added to the reaction mixture. The resulting mixture was extracted with diethyl ether (2×). The ether extract was washed successively with water and a saturated aqueous solution of NaHCO3, dried (MgSO4) and concentrated under reduced pressure to give the title compound (10.4 g, 87% yield). This product was used for the reaction described in the following example. A small sample was triturated with hexane to give off-white crystals; mp 154°-156° C.; nmr (CDCl3) δ 2.3 (s, 3H), 2.9 (m, 4H), 7.2 (m, 2 H), 7.6 (m, 1H); ir (CHCl3) 3570, 3480, 1170 cm-1 ; uvλmax (MeOH) 273 nm (ε 570), 266 (590).

Workup

additionIce was added to the reaction mixture
extractionThe resulting mixture was extracted with diethyl ether (2×)
extractionThe ether extract
washwas washed successively with water
dry with materiala saturated aqueous solution of NaHCO3, dried (MgSO4)
concentrationconcentrated under reduced pressure

Sources & evidence

ORD record: ord-adb4b70fd3e544da971fe32bde437d85
Source dataset: uspto-grants-1985_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04499310

Reaction notes

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