반응 #10321

반응 방정식

1-(2-thienylthio)acetone

→

3-methylthieno[2,3-b]thiophene

수율 42.0%

용매

chlorobenzene

반응 조건

후처리

1. 1
   온도The reaction was heated
2. 2
   온도to reflux overnight
3. 3
   기타The chlorobenzene layer was decanted off
4. 4
   workup.ADDITIONfurther chlorobenzene (15 mL x2) was added to the polyphosphoric acid residue
5. 5
   온도at reflux for 30 minutes
6. 6
   농축The combined chlorobenzene extracts were concentrated in vacuo
7. 7
   기타purified by flash column chromatography on silica
8. 8
   세척eluting with 40% dichloromethane/isohexane

실험 절차

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).

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