反応 #2467968

反応方程式

methyl 4-hydroxy-5-(methoxycarbonyl)-3-nitrothiophene-2-carboxylate

potassium carbonate

Dimethyl sulfate

→

solid

収率 45.0%

Methyl 4-methoxy-5-(methoxycarbonyl)-3-nitrothiophene-2-carboxylate

収率 45.0%

溶媒

acetone

反応条件

後処理

1. 1
   workup.ADDITIONwas added to the above reaction mixture slowly
2. 2
   workup.ADDITIONa catalytic amount of KI was added
3. 3
   温度The mixture was refluxed for 4 h
4. 4
   その他the cooled reaction mixture
5. 5
   ろ過was filtered
6. 6
   洗浄the solids were washed with acetone
7. 7
   その他Acetone was removed under reduced pressure
8. 8
   その他the residue was chromatographed over silica gel column

実験手順

To a solution of methyl 4-hydroxy-5-(methoxycarbonyl)-3-nitrothiophene-2-carboxylate (650 mg, 2.5 mmol) in acetone (20 mL) was added potassium carbonate (0.68 g, 5 mmol) at it Dimethyl sulfate (0.36 mL, 3.73 mmol) was added to the above reaction mixture slowly with stirring and a catalytic amount of KI was added. The mixture was refluxed for 4 h and the cooled reaction mixture was filtered and the solids were washed with acetone. Acetone was removed under reduced pressure and the residue was chromatographed over silica gel column using hexane-ethyl acetate (90:10) as eluents to give the product as a pale yellow color solid (0.3 g, 45%), mp 80-82° C. 1H NMR (400 MHz, CDCl3): δ 4.08 (3H, s), 3.94 (3H, s), 3.92 (3H, s).

出典