الفهرس 
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Abstract
In response to the USA pollution prevention act in 1990, a lot of attention has been given to the environmental impact of chemical industry activities; consequently, the interest in green chemistry has grown. In their publication “Green Chemistry, Theory and Practice” in 1998, Anastas and Warner introduced their well-known twelve principles. As Green chemistry is a concept that crops up with increasing frequency; the work presented in this thesis involves the synthesis of biologically relevant heterocycles with respect of environmentally friendly techniques.
Part (1): Visible-Light, Metal-Catalyst Free, One-Pot Synthesis of Polyfunctionally Substituted Cinnolines.
It has been found that when the ethyl 1-aryl-5-cyano-4-methyl-6-oxo-1,6-dihydropyridazine-3-carboxylates (94) and nitrostyrene derivatives 95 are irradiated with white light (LED 30 W) in EtOH in the presence of piperidine (30% mol) in open air for 8 h at room temperature, the corresponding polyfunctionally substituted cinnolines are obtained in excellent yields (90-95%) via C-H activation of pyridazine methyl group and nitrostyrene (–N=O) function (Scheme I).
Scheme I. Synthesis of cinnoline derivatives (96a-k).
The method showed diverse advantages such as inexpensive and laboratory available starting materials, simple working up the reaction and good functional group tolerance. The use of visible-light instead of thermal heating constitutes a green and trending synthesis of great interest.
Part (2): Microwave-assisted efficient one-pot synthesis of N2-(tetrazol-5-yl)-6-aryl/heteroaryl-2,3-dihydro-1,3,5-triazine-2,4-diamines.
An efficient one-pot synthesis of N2-(tetrazol-5-yl)-6-aryl/heteroaryl-1,3,5-triazine-2,4-diamine 120 derivatives was developed by reacting 5-amino-1,2,3,4-tetrazole 119 with aromatic aldehydes 118 and cyanamide 117 in pyridine under controlled microwave heating with high yields (Scheme II). X-ray crystallography confirmed the structure of the obtained products (Fig. I).
The process proved to be an efficient synthetic route displaying high atom economy, short reaction times and a simple work-up procedure. This protocol appeared to be general with a diversity of aliphatic amines, aromatic amines and heterocyclic amines with aldehydes.