反应详情

3-Hydroxy-5-methoxybenzoic acid methyl ester is reacted with allyl bromide in the presence of potassium carbonate to give 3-allyloxy-5-methoxybenzoic acid methyl ester. B.p. 128°-30°C/0.4 mmHg. The ester is hydrolized to the corresponding acid with 20% potassium hydroxide in aqueous ethanol. The acid (m.p. 85°-7°C) when heated for 2 hours at 230°C undergoes Claisen rearrangement and cyclization to the title compound which melts at 195°-7°C.