반응 #2254178

반응 방정식

Ethylene glycol

p-toluenesulfonic acid

2-brom-3-methyl-5-formylthiophene

→

2-(5-bromo-4-methyl-thiophen-2-yl)-[1,3]dioxolane

용매

toluene

반응 조건

후처리

1. 1
   온도After 18 hours at reflux
2. 2
   기타the reaction is quenched with water
3. 3
   기타The organic phase is separated
4. 4
   추출the aqueous phase is extracted three times with ethyl acetate
5. 5
   건조The combined organic phases are dried over Na2SO4
6. 6
   농축concentrated in vacuo
7. 7
   기타The crude product is purified on a semi-preparative HPLC

실험 절차

Ethylene glycol (2.18 ml) and p-toluenesulfonic acid (0.74 g) is added to a solution of 2-brom-3-methyl-5-formylthiophene (4.0 g) in toluene (98 ml) in a Dean-Stark apparatus. After 18 hours at reflux, the reaction is quenched with water. The organic phase is separated and the aqueous phase is extracted three times with ethyl acetate. The combined organic phases are dried over Na2SO4 and concentrated in vacuo. The crude product is purified on a semi-preparative HPLC to yield 2-(5-bromo-4-methyl-thiophen-2-yl)-[1,3]dioxolane (4.04 g) as a yellow oil. MS (HPLC/MS): 250 (MH+). Retention time: 4.02 min.

출처