A Facile Synthesis of Methyl 2-Substituted-4-benzoxazolecarboxylates.

Methyl 2-substituted-4-benzoxazolecarboxylates were synthesized from methyl 2- amino-3-hydroxybenzoate and the corresponding acid chloride or ortho acetal with pyridinium p-toluenesulfonate as an acid catalyst. Decomposition due to hydration at the 2-position was seen for some compounds during purification.