5-Nitrothiophene-2-carboxaldehyde → 5-Nitro-2-thenoic acid

Reaction equation

Cl[O-:2].[Na+].Br[O-].I[O-].[N+:8]([C:11]1[S:15][C:14]([CH:16]=[O:17])=[CH:13][CH:12]=1)([O-:10])=[O:9]>C(O)(=O)C>[N+:8]([C:11]1[S:15][C:14]([C:16]([OH:2])=[O:17])=[CH:13][CH:12]=1)([O-:10])=[O:9]

Participants

Procedure

It has also been observed, in accordance with another aspect of the present invention, that a mixture of halogen and alkali metal hydroxide i.e. an alkali metal hypohalide such as sodium hypochlorite, hypobromite or hypoiodite when it is added to an aqueous suspension of 5-nitro-2-formyl-thiophene maintained at a pH between 4.5 and 6.5 by means of acetic acid or an acetic acid/alkali metal acetate mixture, provides pure 5-nitro-2-thenoic acid in a yield of at least 75%.