Triphenylphosphonium bromide → 3-Phenyl-3-cyclopentenecarboxylic acid

Temperature

170 °C

3-(Benzoylmethyl)-4,5-dihydro-2(3H)-furanone (5.00 g, Step A) and triphenylphosphine hydrobromide (8.41g) are mixed and heated to 170° C. in an oil bath under nitrogen for 1 hour. The mixture is cooled and powdered. The powder is dissolved in dimethylsulfoxide (50 mL) and diluted with tetrahydrofuran (30 mL). The solution is stirred under nitrogen and cooled in an ice.bath. Dimsyl sodium (25 mL of 2M, see Example D, Step C) is added dropwise over 20 minutes keeping the internal temperature below 14° C. The mixture is stirred at 25° C. for 2 hours and the solvents evaporated. The residue is treated with water (80 mL) containing saturated aqueous sodium bicarbonate (10 mL) and extracted with dichloromethane (3×50 mL). The extracts are washed with dilute aqueous sodium bicarbonate. The aqueous layers are washed with dichloromethane (30 mL) and acidified with concentrated hydrochloric acid. The aqueous layers are extracted with dichloror:ethane (3×50 mL), the extracts dried over magnesium sulfate, filtered, and evaporated to a brown oil. The oil is washed through silica gel (30 g) with 2:1 chloroform:ethyl acetate to give 3.1 g of 3-phenyl-3-cyclopentenecarboxylic acid as a brown solid.

1. temperatureThe mixture is cooled
2. customthe internal temperature below 14° C
3. stirringThe mixture is stirred at 25° C. for 2 hours
4. customthe solvents evaporated
5. additionThe residue is treated with water (80 mL)
6. additioncontaining saturated aqueous sodium bicarbonate (10 mL)
7. extractionextracted with dichloromethane (3×50 mL)
8. washThe extracts are washed with dilute aqueous sodium bicarbonate
9. washThe aqueous layers are washed with dichloromethane (30 mL)
10. extractionThe aqueous layers are extracted with dichloror
11. dry with materialethane (3×50 mL), the extracts dried over magnesium sulfate
12. filtrationfiltered
13. customevaporated to a brown oil
14. washThe oil is washed through silica gel (30 g) with 2:1 chloroform

ORD record

ord-e2d748d07b92476195091ac3fb50ba58

Source dataset

uspto-grants-1994_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05314896