INTRODUCTION:

Green chemistry is defined as the design of chemical product and process to reduce or eliminate the use and generation of hazardous substances. Green chemistry called the sustainable chemistry. The hazardous chemical substances reduce activity. Green chemistry plays important role in the minimize pollution, rate of reaction reduction, rate of pollution decreases in chemical labs. It is effective in whole world to minimize the effect on the human body.

Pollution effect critically for environment. In green chemistry design the raw material that minimize the utilization of harmful substances.

Green chemistry proved the number of challenges in the research, industry. The Paul T. Anastos and John Warner. Used the green chemistry including in medicine or the chemical industry for design, the apparatus to eliminate or minimize pollution or environmental hazards. The twelve-principle proposed by Paul T. Anastos and John Warner in 1991 environmental protection agency (EPA) [1]. Along with they practice chemistry labs, innovation a drug, drug discovery, research and development, industry and daily life. These principle and applications useful in biodegradation of Harmful chemicals and pollutants which increases amount of toxins which dangerous to human health. [1]

In practice labs human safety and the human health has first preference, also focus on elimination of environmental chemical hazardous. Toxic chemicals harmful to the humans and all living things. Microwave technique useful in these new approach towards the designing material. Sonication technique identify different work in practice laboratories. [2,7]

PRINCIPLES OF GREEN CHEMISTRY:

1. Prevention:

Prevention is better to prevent waste than to treat or clean up waste after it has been created.

2. Atom economy:

Reduce waste at the molecular level, transformation of raw material into product. Minimize hazardous effect, less chemicals. Synthetic methods should be designed to maximize the incorporation of all materials used in the process into the final product.

3. Less hazardous chemical synthesis:

Now a days, medicine and chemicals are hazardous to the human health. Reduce toxicity and beneficial to the human health and environment. Wherever practicable, synthetic methods should be designed to use and generate substances that possess little or no toxicity to human health and the environment.

4. Designing safer chemicals:

Designing the pharmaceutical product safe and non-toxic. In industrial level to avoid the accidents from toxic chemicals.

5. Safer solvents and auxiliaries:

The use of auxiliary substances Eg. solvent, separation agents should be made unnecessary wherever possible and innocuous when used.

6. Use renewable feedstock:

Raw material used or utilized renewable technique and economically practicable.

7. Design for degradation:

Design the chemical product in such a way that it should not get involve to damage environment. Chemical products should be designed so that at the end of their function they break down into innocuous degradation products and do not persist in the environment.

8. Reduce derivatives:

Unnecessary use of blocking group, protection/ deprotection, temporary modification of physical/ chemical processes should be minimized or avoided if possible, because such steps require additional reagents and can generate waste.

9. Design for energy efficiency:

Energy requirements of chemical processes should be recognized for their environmental and economic impacts and should be minimized. If possible, synthetic methods should be conducted at ambient temperature and pressure.

10. Catalysis:

Catalytic reagents as selective as possible are superior to stoichiometric reagent. Eg. synthetic reagent, organometallics and building blocks.

11. Real-time analysis for pollution prevention:

Analytical methodologies need to be further developed to allow for real-time, in-process monitoring and control prior to the formation of hazardous substances.

12. Inherently safer chemistry for accident prevention:

Substances and the form of a substance used in a chemical process should be chosen to minimize the potential for chemical accidents, including releases, explosions, and fires.[2]

MICROWAVE SYNTHESIS:

Conventional method performed long time consumption. Microwave create a new theories and process.

● Solvent free condition.

● High and pure yield.

● Clean and waste material easily.

Microwave radiations will be generated to the chemical reaction. Synthesized microwave support increases the pure and higher yield. Enhanced reaction rate. Microwave act as high frequency electric fields will heat any material contain mobile electric charges. Polar solvent is heated and compound molecules forced to rotate with the filed and lose energy in collision.

Microwaves use electromagnetic waves. The spectrum of electromagnetic waves in between infrared radiation and radio waves. Microwave have length 1mm to 1m. principle of microwave heating energy can be applied directly to the sample. Heating started and stopped instantly. This microwave technique beneficial to the drug discovery and development. Microwave radiations is non-ionizing form of energy that does not alter the molecular structure of compounds and provides only thermal activation.

New opportunities to the synthetic chemist in drug discovery of new reaction that is can not possible by conventional method. [8,9,10]

MICROWAVE HEATING:

Materials and the microwave reflect waves Eg. copper. Microwave some material are absorb as like water.

APPLICATION:

● Microwave reactions beneficial to the new drug discovery in industrial level and also Research Development

● Faster reaction-In the practical work in experimental data the no solvent needed the faster reaction occurred microwave enhance reaction rate than conventional method.

● High and pure yield: The side product observation not found reaction product recovered in high yield.

● Less time, and energy saving: Microwave radiation directly heat solvent then the reaction occurred. Energy consumption is less.

● Temperature and chemical reaction easily monitored in microwave.

● Ecofriendly and purification of product and less toxic reagent.

● Microwave useful in polymer, nanotechnologies, inorganic synthesis.

● In microwave heating method no need of apparatus parameters.

ORGANIC SYNTHESIS:

In microwave assisted organic synthesis researchers and scientist successful work on the organic reaction. Diels- alder reaction, Ene reaction, Mannich reaction, cycloaddition reaction, Epoxidation, Reduction, Condensation, Esterification reaction.

For this reaction conventional method heating time is 60 min and in microwave method the time get reduced to 5 min. reaction done in only 5 min.

MATERIAL CHEMISTRY:

Catalyst preparation,

Nano technology: microwave technique used in fabrication of nano molecule, objects. Gives definite structure in shorter time.

WASTE MANAGEMENT:

Hazardous industrial waste and domestic material also the nuclear waste can be destroyed by microwave.

● Microwave controls the green house effect by control the CFC and methane gives the catalysis reaction.

SONICATION:

Sonication is the mechanism used in ultrasonic cleaning and loosing particles adhering to surface. These can used in laboratory science application. Sonication bath have including cleaning objects such as spectacles and jewelries. More work of sonication in food industry. [4,5]

SONICATOR:

Sound waves are used to agitate particles in solution such disruption can be used to mix solutions.

Speed to the dissolution of solid into a liquid. As like sugar into water.

High frequency electrical energy is converted into ultrasound waves.

Ultrasonic transducers which bonded on S.S. water tank.

These have frequency waves create liquid bubbles which occasionally expand and colloid.

Remove dissolve gas from liquids. Cleaning the material.

Dissolution of solid into liquid.

Ultrasound frequency greater than 20Hz. Ultrasound irradiation also called ‘sonochemistry’ which is important in organic chemistry.

Recently ultrasonic energies in organic synthesis homogeneously and heterogeneously reactions included. [4,6]

INORGANIC CHEMISTRY:

Sonochemistry used to increase reaction rate and product yield.

ESTERIFICATION:

This reaction takes longer time and low yield by conventional method.

Eg. sulphuric acid, p- toluene sulphonic acid, tosylchlonide, polyphosphoric acid, dicyclohexyl carbodiimide etc. [7]

GENERAL APPLICATION:

I. Revolutionary drug delivery methods more effective and less toxic. Which is beneficial for millions of patients.

II. This is an no waste reaction, quick reaction and little amount of catalyst or the chemicals used or utilized.

III. It is an improved process in pharmaceutical industry.

IV. Green chemistry improves health care and reduce various environmental hazardous issues.

V. Chemists used this technique for new innovation and creative skills.

VI. Ecofriendly for the environment and industrial plants. [2]

REFERENCES:

1. Rakesh K. Sindhu, Sandeep Arora, Chitkaru university, ‘Applications of Green Chemistry and Day to Day Life’ review article.

2. Mustapha Salifu, Usmanu Da. fodiya university, ‘Application of Green Chemistry in Pharmaceutical Industry’, International Journal of Pharmaceutical Science and Research’.

3. Singhal Manmohan, Singh Arjun, Baba Saheb University, ‘Green Chemistry Poteintial For Past, Present, and Future Perspective’’.

4. https://en.m.wikipedia.org>wiki

5. https:// sciencing.com>...>waves

6. https://en.m.wikipedia.org>wiki

7. Ruchi Verma, Lalit Kumar, Manipal University, ‘Green Chemistry Experiments in Postgraduate Laboratories, review article.

8. Monika Gaba, Nilima Dhingra Department of pharmaceutical chemistry, Punjab university “Microwave Chemistry: general features and applications.

9. Suresh D. Dhage Department of chemistry gangakhed “Applications of green chemistry principle in everyday life”. Review article.

10. Ajmer Singh Grewal, Karunesh Kumar Hariyana, “Microwave assisted synthesis: A Green chemistry Approach”. Review article

Received on 18.08.2020 Modified on 08.09.2020

Asian J. Research Chem. 2020; 13(6):494-496.

DOI: 10.5958/0974-4150.2020.00087.5