Although most of us probably don’t even realize it, petroleum-based organic solvents will touch our everyday lives in many ways. For instance, they’re used as industrial cleaning agents, as reagents for chemical reactions and in the manufacturing of a multitude of products – such as many inks used for printing magazines to food labels and packaging, paints and paint thinners, adhesives, furniture polish, lubricants and many other household items. But often these fossil-derived organic solvents aren’t good for our health or the environment. We urgently need more sustainable, safer alternatives. 

Produced in large quantities across the world, dimethylformamide (DMF) and N-Methyl-2-pyrrolidone (NMP) are solvents with a multitude of uses across different industries. For example, DMF is used is in the production of plastics, facilitating key chemical reactions in drug discovery – and NMP is widely used in drug formulation, electronics and materials manufacturing. The world production capacity of DMF is 225,000 tons worldwide per year – and around 125,000 tons/year of NMP.[1,2]

But these organic solvents are under worldwide regulatory pressure due to major concerns over their toxic effects on the reproductive system. The European Chemicals Agency (ECHA) classifies them on the Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) list of substances of very high concern. Additional restrictions came into force for NMP in 2020.[3]

That’s why we’re using green chemistry to find safer, less environmentally damaging replacements to dipolar aprotic organic solvents like DMF and NMP that still deliver on performance.

Cyrene™ (dihydrolevoglucosenone) is a new safer, bio-based potential alternative to DMF and NMP, which was first developed by Circa Group in partnership with Professor James Clark, PhD, at the University of York’s Green Chemistry Centre of Excellence (GCCE).[7]

Cyrene™ is synthesized in a two-step process from renewable cellulose waste, via a manufacturing process that is almost energy neutral and releases water to the environment. Although this green solvent possesses similar physical properties to dipolar aprotic organic solvents, rigorous safety tests demonstrate it has very low toxicity - well below the hazard thresholds defined by the Globally Harmonized System of Classification and Labelling of Chemicals (GHS).

Despite only recently becoming available in the quantities required for solvent usage, Cyrene™ has already been successfully employed as a green solvent substitute in several industrially-relevant applications, including graphene synthesis and carbon cross-coupling reactions.

Graphene – a single atomic layer of carbon arranged in a distinctive honeycomb lattice – has the potential to have a disruptive impact across the sustainable energy, biomedicine, apparel and electronics industries. However, a major bottleneck is that there is currently no cost-effective way of manufacturing it at scale.

But Cyrene™ may help this revolutionary material to realize its full potential. Recently, scientists made the highest quality graphene inks ever produced using the green solvent instead of traditionally-used NMP.[8] As well as yielding a superior quality product, this also significantly decreased the cost of manufacturing. We’re excited about the potential this offers to unleash the power of graphene inks across a range of printed electronics applications.

DMF is widely used in the pharmaceutical and agrochemical industries in chemical cross-coupling reactions. But switching to Cyrene™ may offer a safer, more sustainable green solvent alternative for many applications. For example:

• Cyrene™ is a suitable replacement for DMF in reactions to create amide bonds, which form the backbone of essential biomolecules and are fundamental within drug discovery.[9]
• A mild and robust method employing Cyrene™ may provide a greener, more sustainable alternative to DMF in reactions to form carbon-carbon bonds.[10]
  
• A green, mild and efficient approach uses Cyrene™ instead of DMF for producing urea compounds, which have many uses across pharmaceuticals, agrochemicals, and materials sciences.[11]

Cyrene™ was awarded Bio-based World News’ European Bio-based Innovation Award in 2017 and Environmental Leader’s Top Product of 2019 award – in recognition of its credentials as a safer, greener alternative to petroleum-based solvents that can also offer superior performance.[12,13]

“Cyrene™ meets a number of demanding criteria – it’s safer, less damaging to the environment and it can deliver superior performance in specific applications,” says Jane Murray, PhD, Global Head of Green Chemistry at Merck KGaA, Darmstadt, Germany.

“We are excited to see Cyrene™ widely employed in large-scale applications. We believe that we are just at the beginning of the number of applications that this product can be used. It is extremely rewarding to help implement safer practices that avoid harming the environment.”

This is only the beginning of the story of Cyrene™. Our researchers are continuing to search for new applications for this greener alternative to harmful petroleum-based solvents.

Cyrene™ a new bio based dipolar aprotic solvent (Blog Post)

_{[1] https://www.chemicalbook.com/ChemicalProductProperty_EN_CB2854115.htm
[2] https://www.sciencedirect.com/topics/medicine-and-dentistry/organic-solvent
[3] https://echa.europa.eu/regulations/reach/understanding-reach
[4] https://m.phys.org/news/2017-02-scientists-categorize-earth-toxic-planet.html
[5] https://www.sciencedirect.com/topics/medicine-and-dentistry/organic-solvent
[6] https://www.chemicalbook.com/ChemicalProductProperty_EN_CB2854115.htm
[7] https://www.ncbi.nlm.nih.gov/pubmed/25007289
[8] https://www.ncbi.nlm.nih.gov/pubmed/30518870
[9] https://pubs.rsc.org/en/content/articlelanding/2018/ob/c8ob00653a#!divAbstract
[10] https://pubs.rsc.org/en/content/articlelanding/2018/ob/c8ob00653a#!divAbstract
[11] https://pubs.rsc.org/en/content/articlelanding/2017/gc/c7gc00908a#!divAbstract
[12] https://www.sustainabilityconsult.com/news/265-press-release-circa-group-s-biosolvent-cyrene-wins-bio-based-innovation-of-the-year
[13] https://www.york.ac.uk/chemistry/news/deptnews/2019/green-solvent-wins-environmental-leader-award/}