反応 #156687

反応方程式

thionylchloride

2-Bromo-4,5-dihydro-thieno[2,3-c]pyran-7-one

Lithium hydroxide

HCl

→

5-Bromo-3-(2-chloro-ethyl)-thiophene-2-carbonyl chloride

溶媒

THF water methanol

Toluene

反応条件

後処理

1. 1
   抽出the aqueous phase was extracted with ethyl acetate
2. 2
   乾燥dried over sodium sulfate
3. 3
   その他the solvent removed
4. 4
   その他The obtained crude product
5. 5
   温度was heated
6. 6
   その他the volatile components removed in vacuum

実験手順

A mixture of 2-Bromo-4,5-dihydro-thieno[2,3-c]pyran-7-one (400 mg), Lithium hydroxide (246.7 mg) in THF/water/methanol (1.7 mL/1.7 mL/0.2 mL) was stirred for 6 h at room temperature. Then the reaction mixture was acidified with 2 N HCl and the aqueous phase was extracted with ethyl acetate, dried over sodium sulfate and the solvent removed. The obtained crude product was heated to reflux with thionylchloride (6.2 mL) for 2 h. Toluene was added and the volatile components removed in vacuum. This step was repeated twice.

出典