Reaction #2770

Reaction equation

sodium carbonate

3,4-dihydro-2H-pyran

sulfuric acid

Poly(p-hydroxystyrene)

→

p-tetrahydropyranyloxystyrene p-hydroxystyrene

Solvents

water

dimethoxyethane

Conditions

Workup

1. 1
   Concentrationthe reaction solution was concentrated under reduced pressure
2. 2
   OtherThe residue obtained
3. 3
   Otherto precipitate crystals
4. 4
   FiltrationThe crystals were filtered off
5. 5
   Washwashed with water
6. 6
   Otherdried under reduced pressure

Procedure

Poly(p-hydroxystyrene) (weight average molecular weight: 9,600) in an amount of 9 g was dissolved in 100 ml of dimethoxyethane, and thereto 12.6 g of 3,4-dihydro-2H-pyran and 0.5 ml of sulfuric acid were added. This solution was stirred for 15 hours at 30°-40° C. After the reaction was completed, the reaction solution was concentrated under reduced pressure. The residue obtained was neutralized with sodium carbonate, and then poured into water to precipitate crystals. The crystals were filtered off, washed with water and dried under reduced pressure. Thus, 11.0 g of poly(p-tetrahydropyranyloxystyrene-p-hydroxystyrene) was obtained as white powder. The ratio of the p-tetrahydropyranyloxystyrene units to the p-hydroxystyrene units in the polymer obtained was determined to be 3:7 by 1H-NMR analysis.

Source