Reaction #2467963

Reaction equation

water

ammonium hydroxide

methyl 3-[(dimethylamino)diazenyl]-4-bromothiophene-2-carboxylate

→

product

Yield 53.0%

3-[(Dimethylamino)diazenyl]-4-bromothiophene-2-carboxamide

Yield 53.0%

Solvents

THF

Conditions

Workup

1. 1
   workup.ADDITIONThe solution was poured into ice
2. 2
   Extractionextracted with ethyl acetate (3×50 mL)
3. 3
   WashThe combined EtOAc 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 (10 mL) was added a solution of methyl 3-[(dimethylamino)diazenyl]-4-bromothiophene-2-carboxylate (500 mg) in THF (5 mL) for 5 min and stirred at rt for 20 h. The solution was poured into ice cooled water and extracted with ethyl acetate (3×50 mL). The combined EtOAc 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 an off-white solid (250 mg, 53%), mp 194-196° C. 1H NMR (400 MHz, DMSO-d6): δ 7.85 (1H, s), 7.75 (1H, br s), 7.56 (1H, br s), 3.56 (3H, br s), 3.21 (3H, br s); LC-MS (positive ion mode): m/z 277, 279 (M+H)+.

Source