A Comparative Study of Conventional and Microwave Assisted Synthesis of Basic Heterocyclic Rings at Undergraduate Level

In general the pharmacologically active compounds are mostly heterocyclic in nature. The heterocyclic compounds shows different pharmacological activities such as Analgesic, Anti-inflammatory, Antipyretic, Anti-bacterial, Antifungal, Anti allergic, Insecticide, Herbicide etc. Now a day's Microwaves are commonly used for synthesis organic compounds due to its beneficts like Reaction rate acceleration, milder reaction condition, higher chemical yield, lower energy usage, different reaction selectivities, design versatilies for wide range of application. Therefore an attempt has been made to syntheisze some basic heterocyclic rings by using microwave energy. We have synthesized some basic heterocyclic rings like 2,3-Diphenylquinoxaline, 3-Methyl-1-phenyl pyrazole-5-one, 5,5- Diphenyl hydantoin, Benzimidazole, 2-Methylbenzimidazole, 2-Phenylbenzimidazole and 1,2,3,4- Tetrahydrocarbazole conventionally as well as by using microwave energy.

The completion of reaction was checked by TLC and purity of compounds was checked by melting point. Time required for the reaction and chemical yield were compared by both methods. It was observed that the compounds can be synthesized successfully by microwave method where time is reduced by 5-15 times and chemical yield is increased by 5-13%.