Yield:58249-83-5 26%

Reaction Conditions:

Stage #1: 2-benzofuran-1(3H)-onewith sodium hydroxide in water at 60; for 0.5 h;
Stage #2: benzoyl chloride in water; for 1 h;

Steps:

4.2.1 Synthesis of 2-benzoyloxymethylbenzoyl chloride 3

Phthalide 1 (10g, 0,074mol) was dissolved in 20% NaOH (54mL, 0.26mol) and the solution was heated at 60°C for 30min. Next, water (440mL) was added and after 10min of vigorous stirring, benzoyl chloride (11.2mL, 0.096mol) was added. The mixture was stirred and after 1h was diluted with water (440mL). Next, 10% HCl was added to reach pH 2 (around 70mL). The white precipitate was filtered off under reduced pressure and crystallized from the mixture of ethanol and water to afford 2-benzoyloxymethylbenzoic acid 2 in 26% yield (5.6g) as colorless crystals, mp=130-131°C; ¹H NMR (CDCl₃)¹⁹: δ=5.71 (s, 2H), 7.48-7.56 (m, 3H), 7.60-7.66 (m, 1H), 7.66-7.70 (m, 2H), 8.12-8.14 (m, 2H), 8.33 (s, 1H).

References:

Rachwalski, Michal;Jarzynski, Szymon;Lesniak, Stanislaw [Tetrahedron Asymmetry,2013,vol. 24,# 7,p. 421 - 425]