Reacción #7832

Ecuación de reacción

3,5-dimethoxy-N-(2-methoxyphenyl)-4-methylbenzamide

p-toluenesulfonic acid monohydrate

→

2-(3,5-dimethoxy-4-methylphenyl)-1,3-benzoxazole

Disolventes

toluene

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturawas refluxed until no starting material
2. 2
   Filtraciónfiltered
3. 3
   Lavadowashing with warm chloroform
4. 4
   OtroRemoval of solvent from filtrate
5. 5
   Otroafforded a yellow solid
6. 6
   OtroPurification of crude solid by flash chromatography on silica gel using 1:3 EtOAc

Procedimiento

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.

Fuente