Yield:894789-43-6 89%

Reaction Conditions:

with sulfuric acid in water at 80; for 4 h;

Steps:

27

A suspension of benzisoxazole a (1.6 g, 7.8 mmol) in 70% H₂SO₄ (30 mL) was heated at 80 ⁰C for 4 h. It was cooled, poured onto crushed ice. The solid was collected by filtration, washed with water, and dried to afford 1.3 g (89%) of benzisoxazole acid b as a white solid.

References:

WO2006/69063,2006,A1 Location in patent:Page/Page column 90