p-Toluenesulfonic acid → 2-Methyl-1,3-benzoxazole-7-carboxylic acid

Participants

Reaction Steps

A solution of 3-amino-2-hydroxy-benzoic acid (9.40 mmol) and PTSA (0.34 mmol) in triethyl orthoacetate (5.77 mL) is heated to reflux for 5 h and concentrated in vacuo. The residue is washed with ether and dried in vacuo to give the desired product which is used without further purification. LC-MS: tR=0.67 min; [M+H]+=178.0.

Provenance & Evidence