In have been stumble on either by unintentional


In the past,
most of the medicinal drugs have been stumble on either by unintentional
discovery or identifying the active ingredients from customary cures. Recent
drug discovery is faced with the challenge of designing chemical reactions that
are greatly capable of affording most of the elements of structural complexity
and variety with least synthetic steps for specific target with fascinating
properties.1 In the current past, combinatorial chemistry has been
considered as a powerful strategy for the fast creation of lead compounds in
the drug discovery process.2 Thus, the main driving force behind the
increased curiosity in this field has been the need to discover and develop new
chemical entities with desirable properties in a cost-effective and more
efficient manner, and most importantly within a short period of time.
Presently, most of the drugs in the market are small organic compounds that
contain heterocyclic motifs. However, in combinatorial chemistry, there are
some shortcomings of accessibility and availability of functionalized
heterocyclic building blocks for the synthesis of different libraries. Therefore,
the development of new, efficient and green synthetic reactions remains a vital
challenge to synthetic chemists.3

To achieve such goals, synthetic
chemists explore multicomponent reaction (MCRs) strategies which create the
several bonds in a single reaction step using readily available starting
materials.4 MCR is considered as an efficient tool for the synthesis
of structurally diverse organic molecules as well as small drug like
heterocycles. It also offered remarkable green chemistry features such as
operational simplicity, atom economy, synthetic convergence, bond efficiency,
short synthetic period, fewer workup and purification processes as well as high

Nitrogen-containing heterocyclic
compounds (N-heterocycles) have upheld the interest of researchers through
decades of historical development of organic synthesis.6 They have
been used as medicinal compounds for centuries, and form the basis for many
common natural drugs such as Morphine (analgesic) Captopril (antihypertensive)
and Vincristine (anticancer).7 N-heterocycles occur in a variety of
natural products and drugs and are of great importance in a wide variety of
applications. In view of the general observation that the biological and
pharmacological activities are invariably related with a large variety of
nitrogen heterocyclic systems such as 1,4-dihydropyridine, and coumarin fused
N-hetrocycles etc. A large number of
their new derivatives have been synthesized and extensively studied for various
pharmacological properties.