Preparation of 2-carboxy-3,4-substituted pyrrole haptens and synthesis of porphobilinogen

Article abstract of DOI:10.1016/0040-4039(96)00286-9

2-Carboxy-3,4-substituted pyrrole 1, the porphobilinogen (PBG, 2) like hapten was prepared via condensation of α-acetoxynitro compound (3) with benzyl isocyanoacetate (4) and further functional group transformations in good yields. Also, the hapten 1 was converted to PBG (2).