تفاعل #2254178

معادلة التفاعل

Ethylene glycol

p-toluenesulfonic acid

2-brom-3-methyl-5-formylthiophene

→

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

المذيبات

toluene

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةAfter 18 hours at reflux
2. 2
   أخرىthe reaction is quenched with water
3. 3
   أخرىThe organic phase is separated
4. 4
   استخلاصthe aqueous phase is extracted three times with ethyl acetate
5. 5
   تجفيفThe combined organic phases are dried over Na2SO4
6. 6
   تركيزconcentrated in vacuo
7. 7
   أخرىThe crude product is purified on a semi-preparative HPLC

الإجراء التجريبي

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.

المصدر