Page 54 - Org 3 theoritical book 2024-25
        P. 54
     Clinical Pharmacy PharmD - 2024/2025                  Level 2                Pharmaceutical Organic Chemistry-3 (PC 305)
                                                 Thiamin                                                       Penicillin
                                             Benzo- Fused Diazoles
                                                   Benzimidazoles:
                                                          4      3
                                                                N
                                                     5
                                                                    2
                                                    6
                                                                N 1
                                                         7      H
            Benzimidazoles  are  readily  obtained  by  heating  o-phenylenediamines  with  carboxylic  acids,  e.g.
            benzimidazole itself is prepared by heating o-phenylenediamine with formic acid:
                                                                                        N
                                                   O
                                      NH 2    +       C    H                            N
                                                  HO             - 2H O
                                                                      2
                                                                                        H
                                     NH 2          O                                 N
                                               +      C   R                                R
                            o-phenylenediamine                  - 2H O
                                                  HO                2                N
                                                                                     H
            The  5,  6-dimethylbenzimidazole  is  a  part  of  the  structure  of  vitamin  B12
            (cobalamin)





