Reaction #2467987

Reaction equation

water

ammonium hydroxide

methyl 4-[(dimethylamino)diazenyl]thiophene-3-carboxylate

→

solid

Yield 25.0%

4-[(Dimethylamino)diazenyl]thiophene-3-carboxamide

Yield 25.0%

Solvents

THF

Conditions

Workup

1. 1
   workup.ADDITIONThe solution was poured into ice
2. 2
   Extractionextracted with chloroform
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

Procedure

To an ice cold (0-5° C.) solution of ammonium hydroxide (5 mL) was added a solution of methyl 4-[(dimethylamino)diazenyl]thiophene-3-carboxylate (110 mg) in THF (2 mL) for 5 min and stirred at rt for 36 h. The solution was poured into ice cooled water and extracted with chloroform. 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 as a pale red color solid (25 mg, 25%), mp 168-172° C. IR (neat) νmax 3324, 3125, 2917, 2851, 1655, 1600, 1367, 1336, 1090 cm−1; 1H NMR (400 MHz, CDCl3): δ 8.55 (1H, br s), 8.19 (1H, d, J=3.6 Hz), 7.15 (1H, d, J=3.6 Hz), 5.84 (1H, br s), 3.56 (3H, br s), 3.19 (3H, br s); LC-MS (positive ion mode): m/z 199 (M+H)+.

Source