Bromide ion → 5-Chloro-3-[2-oxo-2-[4-(trifluoromethyl)phenyl]ethyl]-2(3H)-benzoxazolone

HRID 650048Notes

Reaction equation

BrBr.[F:3][C:4]([F:15])([F:14])[C:5]1[CH:10]=[CH:9][C:8]([C:11](=[O:13])[CH3:12])=[CH:7][CH:6]=1.[CH:16]1[C:21]([Cl:22])=[CH:20][C:19]2[NH:23][C:24]([O:26][C:18]=2[CH:17]=1)=[O:25].[H-].[Na+].[Br-]>C(OCC)C.O1CCOCC1.CN(C=O)C.O>[Cl:22][C:21]1[CH:16]=[CH:17][C:18]2[O:26][C:24](=[O:25])[N:23]([CH2:12][C:11](=[O:13])[C:8]3[CH:7]=[CH:6][C:5]([C:4]([F:14])([F:15])[F:3])=[CH:10][CH:9]=3)[C:19]=2[CH:20]=1

Participants

Conditions

Temperature: 60 °C

Procedure

Bromine (0.67 ml, 13 mmol) was added dropwise to a solution of 4′-(trifluoromethyl)acetophenone (2.5 g, 13 mmol) in diethylether (20 ml) and 1,4-dioxane (10 ml) at room temperature. Chlorzoxazone (2.19 g, 13 mmol) was treated with sodium hydride (400 mg, 13 mmol) in DMF for 15 min. under N2 and transferred by cannulation into the freshly prepared solution of bromide. The reaction mixture was stirred at 60° C. for 3 h, and poured into water (1 vol). The product was extracted with ethyl acetate, and the organic layer washed with water and brine and dried. Concentration gave a solid 4.4 g (93%) which was recrystallized from acetonitrile. mp 188-189° C.; IR(KBr, υ=cm−1) 1776, 1704, 1330, 1226, 1122; 1H NMR (300 MHz, DMSO-d6) δ 5.64 (2H, s), 7.20 (1H, dd, J=8.6 Hz, 2.1 Hz), 7.44 (1H, d, J=8.5 Hz), 7.57 (1H, d, J=2.1 Hz), 7.99 (2H, d, J=8.3 Hz), 8.27 (2H, d, J=8.1 Hz); MS(DCl)m/Z: 356 (MH+) Anal. calcd. for C16H9ClF3NO3: C, 54.03; H, 2.55; N, 3.94. Found: C, 53.73; H, 2,43; N, 3.88.

Workup

extractionThe product was extracted with ethyl acetate
washthe organic layer washed with water and brine
customdried
concentrationConcentration

Sources & evidence

ORD record: ord-401f52509e6544a599f04e9df2872f4d
Source dataset: uspto-grants-2001_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06271249B1

Reaction notes

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