1. INTRODUCTION:

Green chemistry is defined as environmentally benign chemical synthesis.in that microwave is a general-purpose green chemistry for performing reaction in small period of time. Microwave initially started used in or released in 1986 by the groups of Gedye and Giguere/ Majetich although the use is microwave heating in chemical purpose can be back to 1950. And originates from scientist Gedye and Giguere started his research microwave synthesis in the using green chemistry. if focusses on a process whether carried out in industry or chemical laboratory. the reduced the use and generation of harmful substance or byproduct. Green chemical deals with environmentally for chemical synthesis to devise pathway for the prevention of pollution according to Paul T. Anastas¹

Table no: 1

Original author	Gedye and Giguere
Developers	America
Initial release	1946
Stable release back to chemical purpose	1950
Website	www.microwaveassistedsynthesis.com

We will use the microwave assisted synthesis in windows environment. microwave is capable for predicting many properties of metal catalysis and heating principle. all types chemical synthesis reaction including the following

· Basic principle of microwave assisted synthesis.

· Theoretical aspects of microwave dielectric heating.

· Microwave accelerated metal catalysis.

· Heterocyclic chemistry using microwave assisted approaches.

· Microwave assisted reduction.

· Microwave assisted multi component reactions.

· Integrating microwave assisted synthesis and solid supported reagents.

· Microwave assisted solid phase synthesis.

· Scale up of microwave assisted organic synthesis^1,2

2. PRINCIPLE OF MICROWAVE HEATING:

There are three bases of microwave heating mechanical of microwave heating are following points.

· Dipolar polarization

· Ion conduction

· Dielectric loss³

2.1 THEORETICAL ASPECTS OF MICROWAVE DIELECTRIC HEATING:

Theoretical aspects in dielectric heating the degree of Interaction between the microwave electric and magnetic field components with the dielectric or magnetic material determines the rate of energy is dissipated into the material by the various methods including the theoretical aspects of microwave dielectric heating.⁴

2.2 THEORETICAL BASIS OF DIELECTRIC HEATING:

Dielectric heating is depending on use of microwave or also use radio frequency (RF) this wave is heating of insulating other material. There are two types of microwave chambers or cavities can be distinguished in the dielectric heating and the single mode pattern is generated. And multi-mode chambers are large number of resonant patterns is supported.^4,5

2.3 COMPARISON OF MICROWAVE AND CONVENTIONAL HEATING:

Comparison of microwave and conventional heating in that conventional heating is the process are long duration and more energy is used as compared to in that microwave rate of reaction is fast in small duration of time for green chemistry. The mechanism of drying with microwave energy is quite different as compared to conventional drying. There are some properties of microwave heating^4,6

· Rate of reaction is fast.

· Small duration period of time on reaction synthesis.

· Product is more precise.⁶

2.4 MICROWAVE ACCELERATED METAL CATALYSIS:

The review highlights microwave accelerated metal catalyzed transformation of aryl and vinyl halides, the less metal catalysis is use in rate of reaction is fast and most importance in save energy to help environment into green chemistry.^7,8

2.5 HETEROCYCLIC CHEMISTRY USING MICROWAVE ASSISTED APPROACHES:

In that heterocyclic chemistry using microwave assisted is include for organic synthesis. Organic synthesis in that improved rate of reaction and reaction conditions, formation of pure product and more precise⁹

2.6 MICROWAVE ASSISTED REDUCTION:

The microwave assisted reduction is various carbonyl compounds using the solid state supported to the sodium borohydride. Microwave assisted synthesis has been shown to accelerated organic reactions and also used to alternative to conventional heating methods but conventional heating is very slow and large amount of energy are used to the conventional heating^9,10. In that the microwave assisted reduction in that method solvent free techniques in those reactants and reagent that are supported on solid matrix in solid support following techniques are use.¹⁰

· Solvent free reaction shown decrease reaction time.

· Increase product yields.

· Solvent free in that more easily scale up for production solvent-based microwave reaction^9,10

2.7 MICROWAVE ASSISTED MULTI COMPONENT REACTION:

Microwave are used to multi component reaction synthesis in that biologically relevant organic components are used in reaction process. Some points of microwave assisted multi component’s reaction are;¹¹

· High yields

· Less reaction times

· Selectivity and atom economy simpler, purification techniques¹¹

2.8 INTEGRATING MICROWAVE ASSISTED SYNTHESIS AND SOLID SUPPORTED REAGENTS:

Microwave are used to integrating assisted synthesis, and solid supported reagent in that polymer supported reagents are applied to synthesis for the natural product and resulting in purify and efficient synthesis without conventional purification methods but performing microwave heating of reaction are usually are used according to following points¹²

· Heating heterogeneous sample: polymer consideration

· Heating polymer solvent: binary phase method

· Migration of reacting species

· Reaction heating: solvent consideration^12,13

In that solid supported reagent also called as polymer bound or resin bound reagents, the perform synthetic transformation into manner as non-bound counterparts in that microwave assisted synthesis.¹²

2.9 MICROWAVE ASSISTED SOLID PHASE SYNTHESIS:

Microwave are using to solid phase synthesis in that microwave assisted solid phase are starting from various parts are developed

· Resins for solid phase

· Combinatorial chemistry¹³

Are resins for solid phase and combinatorial chemistry are using microwave synthesis are performed rate of reaction is fast in this synthesis and to get product are more precise and purer.^14-17

2.10: SCALE UP OF MICROWAVE ASSISTED ORGANIC SYNTHESIS:

Microwave are the single mode reactors have been very successful in part in the field of method development and optimization. In that including the microwave technology for development of completely new reaction. Routes for organic synthesis. So, increasing demand for large scale microwave production and also chemical substance in this microwave industrial accepted technology that can fast reaction and routinely provide products are optioned.^17-20

Microwave scale up of microwave assisted organic synthesis reactions some properties are following:

· The development of large reactors

· At least in the pilot plant scale to enable multikilogram production of compounds.

· Rate of reaction is fast and increasing demand for large scale^21-24

3. REVIEW OF LITRETURE:

Microwave radiation, an electromagnetic radiation, is widely used as a source of heating in organic synthesis. The basic mechanisms observed in microwave assisted synthesis are dipolar polarization and conduction. Microwave assisted organic synthesis (MAOS) has emerged as a new “lead” in organic synthesis. Microwave Synthesis - A Potential Tool for Green Chemistry S. Ravichandran and E. Karthikeyan Department of Chemistry, Savitha School of Engineering, Savitha University, Thandalam, Chennai - 602 105, India. Jan-Mar 2011²⁵.

The term green chemistry is defined as “the invention, design and application of chemical products and processes to reduce or to eliminate the use and generation of hazardous substances”. The major applications of green chemistry principles and practice renders control, regulation, and remediation, Microwave assisted synthesis is an important tool for green chemistry. Microwave radiation, an electromagnetic radiation, which is widely used as a source of heating in organic synthesis microwave-assisted synthesis: review of recent developments Neha Gupta department of Chemistry, Dev Samaj College for Women, Ferozepur City.18^th-19^th march 20017.²⁶

Solvent-free methods are especially adapted to organic synthesis under Green Chemistry conditions. When coupled to microwave (MW) irradiation, it results in very efficient and clean procedures with noticeable improvements over classical methods. The most suitable cases involve reactions with polar mechanisms with increase of the polarity during the progress of the reaction and late transition states along the reaction coordinates. To cite this article: A. Loopy, C. R. Chime 7 (2004). © 2004 Académie des sciences. Published by Elsevier SAS. All rights reserved in 2004.²⁷

Microwave enhanced one pot three component synthesis of 2-amino-4H-chromenes in aqueous hydrotropic medium is reported. The aqueous hydrotropic medium represents a green solvent under microwave irradiation. The synthetic methodology under microwave irradiation is renewable and sustainable tool of energy saving. Current Research in Green and Sustainable Chemistry June 2020, 100014²⁸

In recent era, synthesis of nanoparticles through green method has gained more attention as it is an environmentally friendly approach. Bio-synthesis of palladium nanoparticles through single step and environmental benign microwave irradiation technique, using hemicellulose as reducing agent is reported and biological activity. Biological activity of derived from hemicellulose via microwave assisted green synthesis in 2021²⁹

4. CONCLUSION:

the review totally focused on microwave assisted synthesis and reaction using under the green chemistry microwave assisted synthesis is help to green chemistry. So, in this review we will use the microwave assisted synthesis in green chemistry is capable for prediction many properties of microwave assisted synthesis. Basic principle of microwave assisted synthesis. Theoretical aspects of microwave dielectric heating. Microwave accelerated metal catalysis. Heterocyclic chemistry using microwave assisted approaches. Microwave assisted reductions. Microwave assisted multi component reactions. Integrating microwave assisted synthesis. And solid supported reagents. Microwave assisted solid phase synthesis. Scale up of microwave assisted organic synthesis. This are points are covered in this review of microwave assisted synthesis.

5. REFERENCE:

1. Madhavi Asurati, Smita Jauhari, K.R Desai a Belief Review: Microwave Assisted Organic Reaction.

2. Microwave Chemistry: General Features and Application Monika Gaba, Neelima Dhingra.

3. V. K. Ahluwalia, Green Chemistry Environmentally Benign Reaction. First Edition 2006, Page no.1.

4. Kappe, C. O. (2004) Angew. Chem. Int. Ed., 43, 6250.

5. Kappe, C. O., Dallinger, D. (2006) Nat. Drug. Disc. Rev.,5, 51.

6. Nagariya A.K., Meena. A.K., Kiran, Yadav A.K., Niranjan. U.S., Pathak A.K., Singh.B., Rao. M.M. (2010) Journal of Pharmacy Research. 3, 575-580.

7. Datta and Ananth Eswaran 2001, Hao Jiang, Zhigang Liu and Shaojin Wang (2017) : Microwave processing effect and impacts on food components, critical reviews in food science and nutrition, DOI : 10: 1080110408398.2017,1319322

8. Raghubar Singh, Heating Mechanism of Microwave

9. Datta A.K. 1998 Understanding and Improvements of Microwave oven heating proceeding of the Appliance Manufacture Conference and Expo.1998 October 12-14; Nashville, TN

10. Datta A.K., V. Rakesh, Principle of Microwave Combination Heating 2013 Page no. 24 Theoretically Aspects of Microwave Dielectric heating: -

11. Amparo Borrell, Maria Dolores Salvador. Advanced ceramic materials sintered by microwave. technology submitted February 13th 2018 Reviewed May 18th 2018 Published October 31st 2018 DOI:10,5772 / intechope 78831

12. Horst Linn, Malte Moller, Dielectric Heating. Page no.6

13. Comparing Microwave to Conventional Heating and Drying. 2012

14. P. Nilson, K. Olofsson, M. Larhed, Microwave Assisted and Metal Catalyze Coupling Reaction pp 103-144

15. The method adopted is the described by H.H. Freedman and R.A. Dubois, Tetrahedron Left, 1975,3251 American Journal of Organic Chemistry P-ISSN : 2163-1271 E-ISSN : 2163.1301 , 2015, 5(4) , 113-115 doi:10, 5923. ajoc. 20150504.01.

16. Shivani Gulati, Stephy Elza John, And Nagula Shankaraiah, Beilsteinj Organic Chemistry 2021; 17:819-865 published online 2021 Apr 19 doi.10.3762/bjac.17.71.Microbiology – Assisted Multicomponent Reaction in Heterocyclic Chemistry and Mechanistic Aspects.

17. Bogley.M. C, Lubinu M.C Microwave Assisted Multicomponent reaction for the synthesis of heterocycles in: Van Dereycken E, Kappe Co, Edrtos microwave assisted synthesis of heterocycles.vol.1. Berlin, Heidelberg: Springer 2006. pp.31-58 (Topics in Heterocyclic Chemistry)

18. Ian R. Baxendale, Ai – Lee and steven V. Ley, A concise synthesis of Carpanone Using solid – Supported Reagents Scavengers.

19. Baure, U. et.al Tetrahedron Lett.2000 41,2713- 2717 solid Supported Reagents Biotage 2014.

20. David H. Drewry. Diane M. Coe, Steve Poon. Glaxo welcome research and development, 5 Moore Dr. Research Triangle park, NC.27709 Glaxo Welcome Medicine Research Centre, Gunnels Wood Road, Stevenage Hetfarelshire SGI 2NY United Kingdom

21. Evelina Colacino, Frederic Lamaty, Jean Martinez, Isabelle parrot, cited by,61. Publish year:2017

22. Jennifer M, Kremsner, Alexander Stadler, C Aiver Kappe. Chapter first online 15 July 2006.

23. D. Villenmin, B. Labiad, Synthetic Commun. 1990, 20(20), 3213.

24. Microwave radiation, an electromagnetic radiation, is widely used as a source of heating in organic synthesis. Green Chemistry S. Ravichandran and E. Karthikeyan Department of Chemistry, Savith. A School of Engineering, Savitha University, Thandalam, Chennai - 602 105, India. Jan-Mar 2011.

25. The Major applications of Green Chemistry Principles And Practice Renders Control, Regulation, and Remediation, Microwave Assisted Synthesis. Microwave-assisted synthesis: review of recent developments Neha Gupta Department of Chemistry, Dev Samaj College for Women, Ferozepur City.18th-19th march 20017.

26. Solvent-free methods are especially adapted to organic synthesis under Green Chemistry conditions. this article: A. Loopy, C. R. Chime 7 (2004). © 2004 Académie Des Sciences. Published by Elsevier SAS. All rights reserved in 2004.

27. The Synthetic Methodology Under Microwave Irradiation is renewable and sustainable tool of energy saving. Current Research in Green and Sustainable Chemistry June 2020, 100014.

28. Biological activity of derived from Hemicellulose via Microwave Assisted Green Synthesis in 2021.

Received on 06.01.2022 Modified on 03.02.2022

Asian J. Research Chem. 2022; 15(2):182-185.

DOI: 10.52711/0974-4150.2022.00031