Phenyl Isothiocyanate → Methyl 2-phenylaminobenzoxazol-6-acetate

Reaction equation

[OH:1][C:2]1[CH:3]=[C:4]([CH2:11][C:12]([O:14][CH3:15])=[O:13])[CH:5]=[CH:6][C:7]=1[N+:8]([O-])=O.[C:16]1([N:22]=[C:23]=S)[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1>C(O)C.[Pd]>[C:16]1([NH:22][C:23]2[O:1][C:2]3[CH:3]=[C:4]([CH2:11][C:12]([O:14][CH3:15])=[O:13])[CH:5]=[CH:6][C:7]=3[N:8]=2)[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1

Participants

Procedure

In ethanol (10 ml) was dissolved methyl 3-hydroxy-4-nitrophenylacetate (592 mg, 2.81 mmol), followed by the addition of 5% palladium/carbon (194 mg). The resulting mixture was subjected to catalytic hydrogenation overnight under stirring at room temperature and normal pressure. After removal the catalyst from the reaction mixture by filtration through Celite under reduced pressure, the filtrated cake was washed with ethanol (30 ml). The filtrate was stirred at room temperature. After addition of phenyl isothiocyanate (370 μl, 3.09 mmol) and stirring at room temperature for one hour, mercuric oxide (yellow) (1.1 g, 5.07 mmol) was added. The reaction mixture was heated under reflux for 3 hours. The mixture was then cooled and the insoluble matter was filtered out under reduced pressure. The filtrate was distilled under reduced pressure. The residue was purified by chromatography on a silica gel column, whereby methyl 2-phenylaminobenzoxazol-6-acetate (480 mg, 61%) was obtained as a white solid from chloroform-ethyl acetate (10:1, v/v) eluate fractions.