反应详情

温度

50 °C

The mixture of 5-bromo-3-phenyl-3H-isobenzofuran-1-one (D3) (14.4 g, 50 mmol), iodine (9 g, 70 mmol), amorphous red phosphorous (7.8 g, 250 mmol), acetic acid (125 mL) and distilled water (15 mL) are taken in this order in a 3-neck flask with a mechanical stirrer and condenser. After stirring overnight at 50° C. (90% product and 10% starting material), the reaction is quenched by adding into water (500 mL), added ether (200 mL) and filtered off phosphorous. The aqueous layer is extracted with ether (3×100 mL) and the combined organic layers are washed with sodium bisulfite solution (100 mL) and water (2×100 mL). The organic phase is extracted using 1N NaOH aqueous solution (4×100 mL), washed again with water (4×100 mL), dried over Na2SO4 and evaporated to get the neutral fraction (2 g, mp 180° C.). The basic phase is acidified with 5N HCl (150 mL) and extracted with DCM (4×100 mL). The combined extracts are washed with water (3×100 mL), dried over Na2SO4 and evaporated to get product (12 g, mp 137° C.). This is further recrystallized from boiling ACN (50 mL) to afford 2-benzyl-4-bromo-benzoic acid (239) (10 g, 83%, mp 145° C.).

1. distillationdistilled water (15 mL)
2. customare taken in this order in a 3-neck flask with a mechanical stirrer and condenser
3. customthe reaction is quenched
4. additionby adding into water (500 mL)
5. additionadded ether (200 mL)
6. filtrationfiltered off phosphorous
7. extractionThe aqueous layer is extracted with ether (3×100 mL)
8. washthe combined organic layers are washed with sodium bisulfite solution (100 mL) and water (2×100 mL)
9. extractionThe organic phase is extracted
10. washwashed again with water (4×100 mL)
11. dry with materialdried over Na2SO4
12. customevaporated
13. customto get the neutral fraction (2 g, mp 180° C.)
14. extractionextracted with DCM (4×100 mL)
15. washThe combined extracts are washed with water (3×100 mL)
16. dry with materialdried over Na2SO4
17. customevaporated