反応 #2467972

反応方程式

K2CO3

dimethylamine

methyl 3-amino-5-phenylthiophene-2-carboxylate

HCl

NaNO2

→

solid

収率 76.0%

Methyl 3-[(dimethylamino)diazenyl]-5-phenylthiophene-2-carboxylate

収率 76.0%

溶媒

H2O

H2O

acetone

反応条件

後処理

1. 1
   workup.DISSOLUTIONto dissolve the product
2. 2
   workup.STIRRINGThe mixture was stirred at 0-5° C. for 1 h
3. 3
   workup.ADDITIONpoured into ice cold water
4. 4
   抽出The solution was extracted with chloroform (3×100 mL)
5. 5
   洗浄The combined CHCl3 layer was washed with water, brine
6. 6
   乾燥dried over sodium sulfate
7. 7
   ろ過The solution was filtered
8. 8
   その他evaporated the solvent
9. 9
   その他The residue was chromatographed over silica gel column

実験手順

To a solution of methyl 3-amino-5-phenylthiophene-2-carboxylate (5 g, 21.4 mmol) and conc. HCl (9 mL, 85.8 mmol) in H2O (51 mL) was added acetone (30 mL) to dissolve the product. Then NaNO2 (1.7 g, 23.6 mmol) was added in portions for 15 min at 0° C. After stirring at 0-5° C. for 1 h, the reaction mixture was added to the solution of K2CO3 (11.2 g, 81.5 mmol) and dimethylamine (8.5 mL, 40%, 77.2 mmol) in H2O (60 mL) at 0° C. The mixture was stirred at 0-5° C. for 1 h and poured into ice cold water. The solution was extracted with chloroform (3×100 mL). The combined CHCl3 layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent. The residue was chromatographed over silica gel column using hexane-EtOAc (90:10) as eluents to give the product as a pale brown color solid (3.8 g, 76%), mp 92-94° C. 1H NMR (400 MHz, DMSO-d6): δ 7.78-7.80 (2H, m), 7.64 (1H, s), 7.46-7.52 (3H, m), 3.84 (3H, s), 3.60 (3H, s), 3.28 (3H, s); LC-MS (positive ion mode): m/z 290 (M+H)+.

出典