反応 #10321

反応方程式

1-(2-thienylthio)acetone

→

3-methylthieno[2,3-b]thiophene

収率 42.0%

溶媒

chlorobenzene

反応条件

後処理

1. 1
   温度The reaction was heated
2. 2
   温度to reflux overnight
3. 3
   その他The chlorobenzene layer was decanted off
4. 4
   workup.ADDITIONfurther chlorobenzene (15 mL x2) was added to the polyphosphoric acid residue
5. 5
   温度at reflux for 30 minutes
6. 6
   濃縮The combined chlorobenzene extracts were concentrated in vacuo
7. 7
   その他purified by flash column chromatography on silica
8. 8
   洗浄eluting with 40% dichloromethane/isohexane

実験手順

A 1M solution of 1-(2-thienylthio)acetone (2.6 g, 15.1 mmol) in chlorobenzene (15 mL) was heated to 110° C. under nitrogen and hot polyphosphoric acid (3 mL) was added. The reaction was heated to reflux overnight. The chlorobenzene layer was decanted off and further chlorobenzene (15 mL x2) was added to the polyphosphoric acid residue and stirred at reflux for 30 minutes. The combined chlorobenzene extracts were concentrated in vacuo and purified by flash column chromatography on silica, eluting with 40% dichloromethane/isohexane, to give 3-methylthieno[2,3-b]thiophene (0.97 g, 42%). 1H NMR (500 MHz, CDCl3) δ 7.34 (1H, dd, J=1.0, 5.2 Hz), 7.16 (1H, d, J=5.2 Hz), 6.94 (1H, t, J=1.1 Hz), 2.40 (3H, d, J=1.1 Hz).

出典