Reaction #4617

Reaction equation

3-(3,4-methylenedioxybenzoyl)pyridine

Sodium hydride

dimethyl sulfoxide

5-carboxypentyltriphenylphosphonium bromide

→

(Z)-7-(3,4-methylenedioxyphenyl)-7-(3-pyridyl)-6-heptenoic acid

Yield 24.6%

Solvents

tetrahydrofuran

water

Conditions

Workup

1. 1
   TemperatureThe reaction mixture was cooled to room temperature
2. 2
   workup.STIRRINGThe mixture was stirred for 10 minutes
3. 3
   workup.ADDITIONAfter completion of addition
4. 4
   workup.STIRRINGthe mixture was further stirred at room temperature for 30 minutes
5. 5
   workup.ADDITIONwas added
6. 6
   Extractionthe neutral substance was extracted twice with toluene (50 ml)
7. 7
   Extractionextracted with ethyl acetate
8. 8
   WashThe organic layer was washed with water
9. 9
   Dryingdried (magnesium sulfate)
10. 10
    Concentrationconcentrated under reduced pressure
11. 11
    ConcentrationThe eluate was concentrated
12. 12
    Otherthe residue was crystallized from ethyl acetate-isopropyl ether

Procedure

Sodium hydride (1 g, 60% in oil) was added to dimethyl sulfoxide (25 ml) under nitrogen and the mixture was heated at 85° C. with stirring for an hour. The reaction mixture was cooled to room temperature and 5-carboxypentyltriphenylphosphonium bromide (5.2 g, 11 mmoles) was added gradually. The mixture was stirred for 10 minutes and a solution of 3-(3,4-methylenedioxybenzoyl)pyridine (2.5 g, 0.11 mole) in tetrahydrofuran (10 ml) was added dropwise thereto. After completion of addition, the mixture was further stirred at room temperature for 30 minutes. After completion of the reaction, water (100 ml was added and the neutral substance was extracted twice with toluene (50 ml). The aqueous layer was adjusted to pH 5.5 with 2N hydrochloric acid and extracted with ethyl acetate. The organic layer was washed with water, dried (magnesium sulfate) and concentrated under reduced pressure. The residue was subjected to silica gel column chromatography using ethyl acetate as the eluent. The eluate was concentrated and the residue was crystallized from ethyl acetate-isopropyl ether to give (Z)-7-(3,4-methylenedioxyphenyl)-7-(3-pyridyl)-6-heptenoic acid (0.4 g, 24.6%). Mp 90°-91° C.

Source