Reaction #5609

Reaction equation

5-benzyloxy-2-chloromethyl-4-pyridone

triphenylphosphine

ethyl acetate

→

5-benzyloxy-2-vinyl-4-pyridone

Yield 66.2%

Solvents

N,N-dimethylformamide

Conditions

Workup

1. 1
   FiltrationThe precipitate was collected by filtration
2. 2
   Washwashed with ethyl acetate
3. 3
   workup.DISSOLUTIONdissolved in dichloromethane (500 ml)
4. 4
   workup.ADDITIONTo the solution were added water (300 ml) and 38% aqueous formaldehyde (100 ml)
5. 5
   Otherthe organic layer was separated
6. 6
   Washwashed with water
7. 7
   Dryingdried over magnesium sulfate
8. 8
   Concentrationconcentrated under reduced pressure
9. 9
   OtherThe product was isolated by column chromatography on silica gel with ethyl acetate as an eluent

Procedure

A solution of 5-benzyloxy-2-chloromethyl-4-pyridone (10.0 g) and triphenylphosphine (10.5 g) in N,N-dimethylformamide (50 ml) was stirred for 5 hours at 90°-100° C. The resulting mixture was poured into ethyl acetate (800 ml). The precipitate was collected by filtration, washed with ethyl acetate and dissolved in dichloromethane (500 ml). To the solution were added water (300 ml) and 38% aqueous formaldehyde (100 ml). The mixture was adjusted to pH 10-10.5 with potassium carbonate. After being stirred for 3 hours at 35°-40° C., the organic layer was separated, washed with water, dried over magnesium sulfate and concentrated under reduced pressure. The product was isolated by column chromatography on silica gel with ethyl acetate as an eluent to give 5-benzyloxy-2-vinyl-4-pyridone (6.02 g).

Source