反应详情

To a mixture of 3,5-diacetoxybenzoic acid (8.00 g, 33.59 mmol) and dimethylformamide (5 drops) in toluene was added freshly distilled thionylchloride (16 mL). The mixture was stirred for 15 min under nitrogen atmosphere at ambient temperature. Then it was refluxed for 2 h at 80° C. in a hot water bath. The excess thionyl chloride was evaporated in vacuo and toluene was added. Insoluble yellow solid was discarded. Toluene was evaporated in vacuo and gave 3,5-diacetoxybenzoyl chloride (8.23 g, 95.5%), which can be recrystallized from hexane. Data are: 1H NMR (CDCl3, 300 MHz) δ 7.75 (d, 2H), 7.29 (t, 1H), 2.34 (s, 6H); 13C NMR (CDCl3, 75 MHz) δ 168.8, 167.0, 151.4, 135.3, 122.8, 122.0, 21.2; mp=89.5-91° C.; HRMS (EI+) found 256.0130 M+, calcd 256.0139 for C11H9O5Cl; Anal. Calcd for C11H9O5Cl: C, 51.48; H, 3.53. Found: C, 51.60; H, 3.68.

1. temperatureThen it was refluxed for 2 h at 80° C. in a hot water bath
2. customThe excess thionyl chloride was evaporated in vacuo and toluene
3. additionwas added
4. customToluene was evaporated in vacuo