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

HRID 362462Notes

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, ν=cm-1) 1776, 1704, 1330, 1226, 1122; 1H NMR (300 MHz, DMSO-d6) δ5.64 (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+)

Workup

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

Sources & evidence

ORD record: ord-7e7449a509d4476ca36181dbc43109ad
Source dataset: uspto-grants-1999_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05869509

Reaction notes

Loading…