Réaction #2467960

Équation de réaction

K2CO3

dimethylamine

methyl 3-aminothiophene-2-carboxylate

HCl

NaNO2

→

solid

Rendement 88.5%

Methyl 3-[(dimethylamino)diazenyl]thiophene-2-carboxylate

Rendement 88.5%

Solvants

H2O

H2O

Conditions de réaction

Traitement

1. 1
   workup.STIRRINGThe mixture was stirred at 0-5° C. for 1 h
2. 2
   workup.ADDITIONpoured into ice cold water
3. 3
   ExtractionThe solution was extracted with chloroform (3×30 mL)
4. 4
   LavageThe combined CHCl3 layer was washed with water, brine
5. 5
   Séchagedried over sodium sulfate
6. 6
   FiltrationThe solution was filtered
7. 7
   Autreevaporated the solvent
8. 8
   AutreThe residue was chromatographed over silica gel column

Mode opératoire

To a solution of methyl 3-aminothiophene-2-carboxylate (0.5 g, 3.18 mmol) and conc. HCl (1.3 mL, 12.73 mmol) in H2O (7.5 mL) was added NaNO2 (0.24 g, 3.50 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 (1.66 g, 12.09 mmol) and dimethylamine (1.3 mL, 40%, 11.46 mmol) in H2O (9 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 (3×30 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 pale orange color solid (600 mg, 88%), mp 74-76° C. 1H NMR (400 MHz, CDCl3): δ 7.33 (1H, d, J=5.6 Hz), 7.24 (1H, d, J=5.6 Hz), 3.87 (3H, s), 3.52 (3H, s), 3.29 (3H, s); LC-MS (positive ion mode): m/z 214 (M+H)+.

Source