p-Toluenesulfonic acid monohydrate → 2-(3-Methoxy-4-methylphenyl)-1,3-benzoxazole
Reaktionsgleichung
O[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[NH:8][C:9](=[O:19])[C:10]1[CH:15]=[CH:14][C:13]([CH3:16])=[C:12]([O:17][CH3:18])[CH:11]=1.O.C1(C)C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1>[CH3:18][O:17][C:12]1[CH:11]=[C:10]([C:9]2[O:19][C:2]3[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=3[N:8]=2)[CH:15]=[CH:14][C:13]=1[CH3:16]Komponenten
4
Edukt 2
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 1
Versuchsvorschrift
A mixture of N-(2-hydroxyphenyl)-3-methoxy-4-methylbenzamide (1.5 g, 5.8 mmol), toluene (30 mL), p-toluenesulfonic acid monohydrate (7.6 g, 40 mmol) and molecular sieves was refluxed overnight. After cooling reaction to rt, filtered washing with warm chloroform and concentrated filtrate in vacuo. The resulting brown oil was purified by flash chromatography on silica gel using 1:4 EtOAc:hexanes to give the desired intermediate, 2-(3-methoxy-4-methylphenyl)-1,3-benzoxazole, as a colorless solid.