反应详情

温度

65 °C

A mixture of 310 mL (2.75 mol) of 3,4-dihydro-2H-pyran, 99.1 g (94 mL, 1.38 mol) of acrylic acid, 5 g of crosslinked poly(4-vinylpyridine hydrochloride) (Fluka Chemical Corp., catalog number 82803, 6 meq/g), and 0.5 g of phenothiazine was warmed until an exothermic reaction caused the temperature to rise to 99° C. An ice bath was used to cool the mixture to 65° C., and the mixture was stirred at 65° C. for 18 hours. After cooling to room temperature, the mixture was filtered to remove the catalyst. NMR analysis of the filtrate showed the presence of 2-tetrahydropyranyl acrylate and 3,4-dihydro-2H-pyran with little or no acrylic acid. The mixture was stirred with anhydrous sodium carbonate and calcium hydride for 1 hour. After removal of excess 3,4-dihydro-2H-pyran in a rotary evaporator, distillation over calcium hydride, anhydrous sodium carbonate, and phenothiazine gave 136.6 g of 2-tetrahydropyranyl acrylate, b.p. 66°-70° C. (3.2 mm).

1. temperaturewas warmed until an exothermic reaction
2. customto rise to 99° C
3. customAn ice bath was used
4. temperatureAfter cooling to room temperature
5. filtrationthe mixture was filtered
6. customto remove the catalyst
7. stirringThe mixture was stirred with anhydrous sodium carbonate and calcium hydride for 1 hour
8. customAfter removal of excess 3,4-dihydro-2H-pyran
9. customin a rotary evaporator, distillation over calcium hydride, anhydrous sodium carbonate, and phenothiazine