The Application of Ethyl Lactate in the Pharmaceutical Industry

The wide interest for green chemistry applications in pharmaceutical and chemical industries is increasing because of the environmental challenges facing the world today. Solvents are required for most of the chemical transformations to increase the contact between the reagents and catalysts. Solvent also ensures a suitable isolation process of products from the reaction mixture.

Ethyl lactate is a bio-based, environmentally benign and economically viable solvent with effectiveness comparable to petroleum-based solvents.Recently synthetic organic chemists are paying attention to use ethyl lactate as reaction medium as it has some useful advantages. Ethyl lactate has been used for asymmetric induction, multi-component reactions, ligand free coupling reactions, light induced synthesis, stereoselective synthesis, cycloaddtion reaction etc. The advantages and limitations of this solvent are also demonstrated. In this article, we demonstrated some representative examples of organic reactions in ethyl lactate media.

Among the non-conventional solvents, ethyl lactate can be considered as one of the most organic solvents synthesised. It is a solvent based on agrochemicals and is derived from plants.It can be synthesised from carbohydrates such as maize waste or sugar crops, rather than being based on petroleum or fossil fuels.It is a clear liquid, or pale yellow, naturally found in a large number of foods such as chicken, soya products, meat and other foods.It is present in small quantities in many foods, such as chicken, soya products, meat and some fruits, or as a flavouring in fermented foods.

As a green solvent, ethyl lactate has a variety of advantages as following:

• 100% biodegradable
• Stable in solvent formulations until exposed to water
• High solvency power for resins, polymers, and dyes
• Easy and inexpensive to recycle
• Low VOC
• Not a hazardous air pollutant

In pharmaceutical product development, chiral chemistry is very important. Among the chiral building blocks for natural products, lactic acid is one of the significant components.

Ethyl lactate also enhances the duration of protection against mosquitoes (e.g. Aedes aegypti). Some pharmaceutical applications, such as parenteral and dialysis solutions, use natural lactic acid and its isomers. Lactic acid esters are used as diluents for many resins and oils.Diluents for paints, dyes, pigments, as cleaning agents and as degreasing solutions for machinery. In order to reduce environmental pollution, there has been an interest in using “green solvents” to replace the unfriendly and dangerous solvents used in traditional chemical production, such as olefins for interest in isomerisation reactions has increased. The olefin isomerisation reaction is one of the most important processes in the pharmaceutical and fine chemical industry.As an atomically economical and selective chemical transformation, olefin metathesis is one of the important processes in the pharmaceutical and fine chemical industries.Different solvents have been used and these include water, methyl tert-butyl ether (MTBE), acetic acid, glycerol, polyethylene glycol, dimethyl carbonate (DMC), 2-methyl tetrahydrofuran (2-MeTHF), methyl decenoate and ethyl acetate (AcOEt). Although many studies have been done on olefin metathesis to elucidate the mechanism or pathways, only a few have been reported on ‘green’ solvents.EL is the cheapest and simplest lactate used to catalyse the transformation of olefins.

Conclusion: Being a promising green media this bio-based solvent ethyl lactate has an important contribution in synthesis and medicinal chemistry as well.