3-Phenoxybenzoic acid → 5-Acetyl-4-methyl-2-(3-phenoxyphenyl)oxazole

HRID 128684

Reaction equation

[O:1]([C:8]1[CH:9]=[C:10]([CH:14]=[CH:15][CH:16]=1)[C:11]([NH2:13])=[O:12])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[O:17](C1C=C(C=CC=1)C(O)=O)[C:18]1[CH:23]=C[CH:21]=[CH:20][CH:19]=1>[OH-].[Na+]>[C:18]([C:19]1[O:12][C:11]([C:10]2[CH:14]=[CH:15][CH:16]=[C:8]([O:1][C:2]3[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=3)[CH:9]=2)=[N:13][C:20]=1[CH3:21])(=[O:17])[CH3:23]

Participants

Conditions

Temperature: 180 °C

Procedure

A mixture of 3-phenoxybenzamide (2.13 g, 10 mmol), 3-phenoxybenzoic acid (4.28 g, 20 mmol), and 3-chloropenta-2,4-dione (0.44 g, 3.3 mmol) was heated to 180° C. under stirring for 23 h. The hot mixture was poured into 1N aqueous sodium hydroxide (100 ml), and extracted with diethyl ether (100+2×50 ml). The combined organic phases were washed with saturated aqueous sodium bicarbonate (50 ml) and brine (50 ml), dried over magnesium sulfate, and evaporated to dryness. Purification by silica gel column chromatography (135 g, 16.7% ethyl acetate in n-hexane) afforded the titled compound as solids in 94% yield: 1H NMR (CDCl3) δ7.88-7.83 (1H, m), 7.77-7.53 (1H, m), 7.49-7.34 (3H, m), 7.18-7.12 (2H, m), 7.07-7.00 (2H, m), 2.55 (3H, s), 2.54 (3 H, s).

Workup

extractionextracted with diethyl ether (100+2×50 ml)
washThe combined organic phases were washed with saturated aqueous sodium bicarbonate (50 ml) and brine (50 ml)
dry with materialdried over magnesium sulfate
customevaporated to dryness
customPurification by silica gel column chromatography (135 g, 16.7% ethyl acetate in n-hexane)

Sources & evidence

ORD record: ord-73a8b1f0a08048a8937510601d49b623
Source dataset: uspto-grants-1995_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05464849

Linked notes

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