Reaction #2467973

Reaction equation

water

ammonium hydroxide

methyl 3-[(dimethylamino)diazenyl]-5-phenylthiophene-2-carboxylate

→

solid

Yield 8.0%

3-[(Dimethylamino)diazenyl]-5-phenylthiophene-2-carboxamide

Yield 8.0%

Solvents

THF

Conditions

Workup

1. 1
   workup.ADDITIONThe solution was poured into ice
2. 2
   Extractionextracted with chloroform
3. 3
   WashThe combined organic 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
9. 9
   OtherThe crude product was recrystallized from chloroform-hexane

Procedure

To an ice cold (0-5° C.) solution of ammonium hydroxide (80 mL) was added a solution of methyl 3-[(dimethylamino)diazenyl]-5-phenylthiophene-2-carboxylate (2.2 g) in THF (15 mL) for 5 min followed by catalytic amount of PEG-400 and the mixture was stirred at rt for 36 h. The solution was poured into ice cooled water and extracted with chloroform. The combined organic 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 (94:6) as eluents to give the product. The crude product was recrystallized from chloroform-hexane to give the product as a yellow color solid (170 mg, 8%), mp 220-222° C. IR (neat) νmax, 3343, 2922, 2855, 1642, 1595, 1221, 1023, 880, 841 cm−1; 1H NMR (400 MHz, CDCl3): δ 8.30 (1H, br s), 7.64-7.66 (2H, m), 7.53 (1H, s), 7.30-7.41 (3H, m), 6.34 (1H, br s), 3.59 (3H, s), 3.20 (3H, s); 13C NMR (100 MHz, CDCl3): δ 164.7, 151.1, 146.7, 133.9, 128.9, 128.5, 125.8, 125.4, 114.7, 43.6, 36.5; LC-MS (positive ion mode): m/z 297 (M+Na)+.

Source