Thionyl Chloride → 4-Amino-3-(1-methyl-4-nitro-2-pyrrolecarboxamido)benzoic acid
Reaction equation
[CH3:1][N:2]1[CH:6]=[C:5]([N+:7]([O-:9])=[O:8])[CH:4]=[C:3]1[C:10]([OH:12])=O.S(Cl)(Cl)=O.[CH3:17][N:18]1[CH:22]=[C:21]([N+:23]([O-:25])=[O:24])[CH:20]=[C:19]1[C:26](Cl)=[O:27].[NH2:29][C:30]1[CH:31]=[C:32]([CH:36]=[CH:37][C:38]=1[NH2:39])[C:33]([OH:35])=[O:34]>>[NH2:29][C:30]1[CH:31]=[C:32]([CH:36]=[CH:37][C:38]=1[NH:39][C:10]([C:3]1[N:2]([CH3:1])[CH:6]=[C:5]([N+:7]([O-:9])=[O:8])[CH:4]=1)=[O:12])[C:33]([OH:35])=[O:34].[NH2:39][C:38]1[CH:37]=[CH:36][C:32]([C:33]([OH:35])=[O:34])=[CH:31][C:30]=1[NH:29][C:26]([C:19]1[N:18]([CH3:17])[CH:22]=[C:21]([N+:23]([O-:25])=[O:24])[CH:20]=1)=[O:27]Participants
Reactant 4
Product 2
Procedure
As a further alternative, the compound of the formula (14) can also be synthesized as will be described next. For example, 1-methyl-4-nitro-2-pyrrolecarboxylic acid is reacted, by using the process disclosed in Tetrahedron, 34, 2389-2391(1978), with thionyl chloride into 1-methyl-4-nitro-2-pyrrolecarboxylic acid chloride, which is then reacted with a 3,4-diaminobenzoic acid to obtain 3-amino-4-(1-methyl-4-nitro-2-pyrrolecarboxamido)benzoic acid or 4-amino-3-(1-methyl-4-nitro-2-pyrrolecarboxamido)benzoic acid as the exemplified compound. Here, the reaction product can also be a mixture of both the benzoic acids. Methylene chloride, chloroform, DMF or the like can be used as a solvent. Other solvents are also usable as long as they do not take part in the reactions. Heating of the thus-obtained amide compound with trilfluoroacetic acid with any solvent, which do not participate in the reaction, provides 1H-2-(1-methyl-4-nitropyrrol-2-yl)benzimidazole-5-carboxylic acid. Further, 1-methyl-4-nitro-2-trichloroacetylpyrrole which is a known compound disclosed in Heterocycles, 27, 1945-1952(1988) is likewise reacted with 3,4-diaminobenzoic acid to obtain 3-amino-4-(1-methyl-4-nitro-2-pyrrolecarboxamido)-benzoic acid or 4-amino-3-(1-methyl-4-nitro-2-pyrrolecarboxamido)benzoic acid. Here, the reaction product can also be a mixture of both the benzoic acids. The reaction product can also be converted into 1H-2-(1-methyl-4-nitropyrrole-2-yl)benzimidazole-5-carboxylic acid likewise. The reaction can also be conducted similarly by using as a starting material an equivalent carboxylic acid other than 1-methylpyrrole-2-carboxylic acid.
Sources & evidence
- ORD record
- ord-ce6c27ffdf324840806ea9df8bf799fb
- Source dataset
- uspto-grants-1998_12
- Patent number
- US05852011
Reaction notes
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