Trifluoroacetic acid → 4-bromo-N-((2-(methylthio)benzo[d]oxazol-6-yl)methyl)-2-nitroaniline

HRID 1848204Notes

Reaction equation

[Br:1][C:2]1[CH:8]=[CH:7][C:5]([NH2:6])=[C:4]([N+:9]([O-:11])=[O:10])[CH:3]=1.C(O)(C(F)(F)F)=O.[BH-](OC(C)=O)(OC(C)=O)OC(C)=O.[Na+].[CH3:33][S:34][C:35]1[O:36][C:37]2[CH:43]=[C:42]([CH:44]=O)[CH:41]=[CH:40][C:38]=2[N:39]=1>C(Cl)Cl>[Br:1][C:2]1[CH:8]=[CH:7][C:5]([NH:6][CH2:44][C:42]2[CH:41]=[CH:40][C:38]3[N:39]=[C:35]([S:34][CH3:33])[O:36][C:37]=3[CH:43]=2)=[C:4]([N+:9]([O-:11])=[O:10])[CH:3]=1

Participants

Conditions

Temperature: 0 °C

Procedure

To a solution of 4-bromo-2-nitroaniline (400 mg, 1.84 mmol) and TFA (1.89 mL) in DCM (8 mL) at −5° C. was added NaBH(OAc)3 (1.17 g, 5.52 mmol). Then to the mixture at 0° C. was added a solution of 2-(methylthio)benzo[d]oxazole-6-carbaldehyde (391 mg, 2.03 mmol) in DCM (7 mL), and the mixture was stirred at 0° C. for 2 h. The mixture was diluted with DCM and washed with H2O, aq NaHCO3 and brine. The organic layer was dried over Na2SO4, filtered and concentrated under reduced pressure. The residue was purified by silica gel chromatography eluting with 20:1 to 10:1 petroleum ether/ethyl acetate to give 4-bromo-N-((2-(methylthio)benzo[d]oxazol-6-yl)methyl)-2-nitroaniline as a yellow solid (704 mg, 97.4%). 1H NMR (300 MHz, DMSO-d6) δ 8.80 (t, 1H), 8.15 (s, 1H), 7.64 (s, 1H), 7.50-7.60 (m, 2H), 7.35 (d, J=8.4 Hz, 1H), 6.90 (d, J=9.3 Hz, 1H), 4.72 (d, J=6.6 Hz, 1H), 2.73 (s, 3H). LCMS (ESI) m/z 394 (M+H)+.

Workup

washwashed with H2O, aq NaHCO3 and brine
dry with materialThe organic layer was dried over Na2SO4
filtrationfiltered
concentrationconcentrated under reduced pressure
customThe residue was purified by silica gel chromatography
washeluting with 20:1 to 10:1 petroleum ether/ethyl acetate

Sources & evidence

ORD record: ord-a04b983552054f3599550eae891a639b
Source dataset: uspto-grants-2015_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08952058B2

Reaction notes

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