p-Toluenesulfonic acid monohydrate → 2-(3,5-Dimethoxy-4-methylphenyl)-1,3-benzoxazole
Reaktionsgleichung
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:17]=[C:18]([O:21][CH3:22])[C:19]=1[CH3:20])[C:6]([NH:8][C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][C:10]=1[O:15]C)=O.O.C1(C)C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1>[CH3:22][O:21][C:18]1[CH:17]=[C:5]([C:6]2[O:15][C:10]3[CH:11]=[CH:12][CH:13]=[CH:14][C:9]=3[N:8]=2)[CH:4]=[C:3]([O:2][CH3:1])[C:19]=1[CH3:20]Komponenten
4
Edukt 2
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 1
Versuchsvorschrift
A mixture of 3,5-dimethoxy-N-(2-methoxyphenyl)-4-methylbenzamide (1.29 g, 4.49 mmol), toluene (22 mL), p-toluenesulfonic acid monohydrate (5.9 g, 31 mmol) and molecular sieves was refluxed until no starting material was observed by TLC. Cooled mixture to rt and filtered, washing with warm chloroform. Removal of solvent from filtrate afforded a yellow solid. Purification of crude solid by flash chromatography on silica gel using 1:3 EtOAc:hexanes gave the desired intermediate, 2-(3,5-dimethoxy-4-methylphenyl)-1,3-benzoxazole, as a colorless solid.