Download (4Mb) - Etheses - Saurashtra University

Chapter – 3 Preparation of small library…..
3.1 AIM OF CURRENT WORK
Isatin has been known for about 150 years and their derivatives
constitute a class of biologically active heterocycles which have been found
associated with antiviral, antibacterial, anthelmintic, amoebicidal, antifungal,
anti-HIV, anticonvulsant, antileukemic, antifertility, herbicidal, antiinflammatory
and CNS depressant derivatives. In addition to these cysticidal and
hypotensive responses have also been reported in certain isatin derivatives.
A large number of C-Mannich bases have been prepared and tested
for analgesic, antispasmodic, anesthetic and antibacterial activity. Certain
Mannich bases with complex amine moieties have shown pronounced
antibacterial activity. Though considerable work has been reported on the
synthesis and pharmacological activity of Mannich bases derived from
compounds containing acidic hydrogen on carbon, only few examples of the
Mannich reaction of compounds containing acidic hydrogen on a nitrogen
atom are known and even fewer have been evaluated for their
pharmacological action.
Schiff bases and Mannich bases of isatin are known to possess a wide
range of pharmacological properties including antibacterial, anti-HIV,
anticonvulsant, antifungal and antiviral activity. This led us to synthesize some
of the hitherto unreported N-Mannich bases of isatin along with their Schiff
bases and to report their anticancer activity. Total reported synthesis is
consisting of two steps where first step includes synthesis of isatin N-Mannich
bases using secondary amines viz. morpholine, piperidine, 1-methyl
piperazine, 1-ethyl piperazine and 1-benzyl piperazine while second step
includes Schiff bases of these N-Mannich bases using 2propylpentanohydrazide
and 2-amino-6-methoxy benzothiazole. Looking to
the diversified biological profile shown by benzothiazoles one more scheme
has been included in this chapter where Schiff bases of N-acetyl isatin have
been prepared.
Preparation of unreported and novel isatin derivatives and their
biological evaluation was the rational behind the built up of this chapter.
Department of Chemistry, Saurashtra University, Rajkot – 360 005 148