Pyridine → methyl 2-(acetylamino)-5-chloro-3-thiophenecarboxylate
Reaction equation
[C:1]([NH:4][C:5]1[S:6][CH:7]=[CH:8][C:9]=1[C:10]([O:12][CH3:13])=[O:11])(=[O:3])[CH3:2].C(Cl)(Cl)[Cl:15].N1C=CC=CC=1.ClCl>C(Cl)(Cl)(Cl)Cl>[C:1]([NH:4][C:5]1[S:6][C:7]([Cl:15])=[CH:8][C:9]=1[C:10]([O:12][CH3:13])=[O:11])(=[O:3])[CH3:2]Participants
6
Procedure
To a stirred solution of 4 parts of methyl 2-acetamidothiophene-3 -carboxylate in a mixture of 80 parts by volume of chloroform and 12 parts by volume of pyridine, 20 parts by volume of a 10 % (W/V) solution of chlorine in carbon tetrachloride is added dropwise. After stirring for further 30 minutes, the mixture is washed with an aqueous sodium bicarbonate solution and, then, with water. Evaporation of the solvent, and recrystallization of the residue from methanol gives methyl 2-acetamido-5-chlorothiophene-3-carboxylate as crystals. Colorless needles, melting point: 110°-110.5°C.
Workup
- additionis added dropwise
- washthe mixture is washed with an aqueous sodium bicarbonate solution
- customEvaporation of the solvent, and recrystallization of the residue from methanol
Sources & evidence
- ORD record
- ord-d01d152cd831486284405324321464df
- Source dataset
- uspto-grants-1976_04
- Patent number
- US03951989
Reaction notes
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