تفاعل #2467981

معادلة التفاعل

HCl

NaNO2

methyl 4-aminothiophene-2-carboxylate

K2CO3

dimethylamine

→

solid

المردود 10.8%

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

المردود 10.8%

المذيبات

H2O

H2O

ظروف التفاعل

المعالجة

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

الإجراء التجريبي

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).

المصدر