Реакция #2467981

Уравнение реакции

HCl

NaNO2

methyl 4-aminothiophene-2-carboxylate

K2CO3

dimethylamine

→

solid

Выход 10.8%

Methyl 4-[(dimethylamino)diazenyl]thiophene-2-carboxylate

Выход 10.8%

Растворители

H2O

H2O

Условия реакции

Обработка

1. 1
   workup.STIRRINGThe mixture was stirred at 0-5° C. for 1 h
2. 2
   workup.ADDITIONpoured into ice cold water
3. 3
   ЭкстракцияThe solution was extracted with chloroform (3×100 mL)
4. 4
   ПромывкаThe combined CHCl3 layer was washed with water, brine
5. 5
   Сушкаdried over sodium sulfate
6. 6
   ФильтрацияThe solution was filtered
7. 7
   Другоеevaporated the solvent
8. 8
   ДругоеThe residue was chromatographed over silica gel column

Методика

To a solution of methyl 4-aminothiophene-2-carboxylate (1.7 g, 10.82 mmol) and cone. HCl (4.6 mL, 43.5 mmol) in H2O (20 mL) was added NaNO2 (0.84 g, 12.17 mmol) in portions for 5 min at 0° C. After stirring for 0.5 h at 0-5° C., the reaction mixture was added to the solution of K2CO3 (5.8 g, 42 mmol) and dimethylamine (4.6 mL, 40%, 40.9 mmol) in H2O (30 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 (80:20) as eluents to give the product as light red color solid (250 mg), which was recrystallized from chloroform-hexane (110 mg), mp 90-92° C. 1H NMR (400 MHz, CDCl3): δ 7.93 (1H, d, J=1.6 Hz), 7.31 (1H, d, J=1.6 Hz), 3.88 (3H, s), 3.31 (6H, br s).

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