Reaktion #7832

Reaktionsgleichung

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

p-toluenesulfonic acid monohydrate

→

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

Lösungsmittel

toluene

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturwas refluxed until no starting material
2. 2
   Filtrationfiltered
3. 3
   Waschenwashing with warm chloroform
4. 4
   SonstigeRemoval of solvent from filtrate
5. 5
   Sonstigeafforded a yellow solid
6. 6
   SonstigePurification of crude solid by flash chromatography on silica gel using 1:3 EtOAc

Vorschrift

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.

Quelle