Reaction #2467962

Reaction equation

methyl 3-aminothiophene-2-carboxylate

bromine

→

solid

Yield 33.3%

Methyl 3-amino-4-bromothiophene-2-carboxylate

Yield 33.3%

Solvents

acetic acid

acetic acid

Conditions

Workup

1. 1
   workup.ADDITIONThe reaction mixture was poured into ice cold water
2. 2
   Extractionextracted with chloroform (3×100 mL)
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

Procedure

To a solution of methyl 3-aminothiophene-2-carboxylate (1 g, 6.36 mmol) in acetic acid (10 mL) was added a solution of bromine (0.32 mL, 6.36 mmol) in acetic acid (1 mL) slowly for 5 min at rt and stirred at the same temperature for 16 h. The reaction mixture was poured into ice cold water and extracted with chloroform (3×100 mL). 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 hexane-EtOAc (95:5) as eluents to give the product as a pale yellow color solid (0.5 g, 33%), mp 58-60° C.

Source