Reaction #2467978

Reaction equation

water

methyl amine

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

→

solid

Yield 76.0%

{3-[(dimethylamino)diazenyl](2-thienyl)}-N-methylcarboxamide

Yield 76.0%

Solvents

THF

THF

Conditions

Workup

1. 1
   workup.ADDITIONThe solution was poured into ice
2. 2
   Extractionthe solution was extracted with chloroform (3×100 mL)
3. 3
   WashThe combined chloroform layer was washed with water, brine
4. 4
   Dryingdried over sodium sulfate
5. 5
   FiltrationThe solution was filtered
6. 6
   Otherevaporated the solvent
7. 7
   OtherThe residue was chromatographed over silica gel column
8. 8
   Otherto give the product, which
9. 9
   Otherwas recrystallized from chloroform-hexane

Procedure

To an ice cold (0-5° C.) solution of methyl amine (3 mL) in THF (5 mL) was added a solution of methyl 3-[(dimethylamino)diazenyl]thiophene-2-carboxylate (500 mg) in THF (5 mL) for 5 min and stirred at rt for 36 h. The solution was poured into ice cooled water and the solution was extracted with chloroform (3×100 mL). The combined chloroform 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 chloroform-methanol (98:2) as eluents to give the product, which was recrystallized from chloroform-hexane gave the product as a pale orange color solid (380 mg, 76%), mp 98-102° C. IR (neat) νmax 3297, 3082, 2929, 1637, 1380, 1348, 1299, 1221, 1109, 1016, 882, 776 cm−1; 1H NMR (400 MHz, CDCl3): δ 8.35 (1H, br s), 7.29 (1H, d, J=5.2 Hz), 7.27 (1H, d, J=5.2 Hz), 3.57 (3H, br s), 3.21 (3H, br s), 3.00 (3H, d, J=4.8 Hz); LC-MS (positive ion mode): m/z 213 (M+H)+.

Source