Methyl trifluoromethyl ketone → 1,1,1-Trifluoro-2-(5-nitrobenzothiazol-2-yl)propan-2-ol

HRID 1720020Notes

Reaction equation

[N+:1]([C:4]1[CH:5]=[CH:6][C:7]2[S:11][CH:10]=[N:9][C:8]=2[CH:12]=1)([O-:3])=[O:2].C([N-]C(C)C)(C)C.[Li+].[F:21][C:22]([F:27])([F:26])[C:23](=[O:25])[CH3:24].[Cl-].[NH4+]>O1CCCC1>[F:21][C:22]([F:27])([F:26])[C:23]([C:10]1[S:11][C:7]2[CH:6]=[CH:5][C:4]([N+:1]([O-:3])=[O:2])=[CH:12][C:8]=2[N:9]=1)([OH:25])[CH3:24]

Participants

Conditions

Temperature: -100 °C

Procedure

A solution of 5-nitrobenzothiazole (120 mg) in dry tetrahydrofuran (10 mL was cooled to -100° C. and then treated dropwise with lithium diisopropylamide (0.36 mL, 2.0M). The reaction mixture was stirred for 40 minutes at -100° C., and then treated with a solution of trifluoroacetone (75 mg) in dry tetrahydrofuran (1 mL). The reaction mixture was maintained at -100° C. for 30 minutes, treated with saturated aqueous ammonium chloride (10 mL), warmed to room temperature, and extracted with diethyl ether. The extracts were combined, washed (brine) dried (Na2SO4), and evaporated to leave a brown solid. Chromatography, eluting with chloroform, followed by chromatography, eluting with toluene, gave the title compound as a solid (100 mg); m.p. 66°-69° C.; NMR: 1.87 (s,3), 8.10 (s,1), 8.33 (dd,1), 8.46 (d,1), 8.87 (d,1); MS (EI, high resolution): 292.0144 (theoretical 292.01292). Analysis for C10H7F3N2O3S: Calculated: 41.10; H, 2.41; N, 9,59; Found: C, 39.32; H, 3.09; N, 8,26.

Workup

temperatureThe reaction mixture was maintained at -100° C. for 30 minutes
temperaturewarmed to room temperature
extractionextracted with diethyl ether
washwashed (brine)
dry with materialdried (Na2SO4)
customevaporated
customto leave a brown solid
washChromatography, eluting with chloroform
washeluting with toluene

Sources & evidence

ORD record: ord-dfc08b69b0f448cb8514e4a776de4643
Source dataset: uspto-grants-1996_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05504089

Reaction notes

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