Towards more sustainable synthesis of diketopyrrolopyrroles

Pop, Flavia; Humphreys, Joshua; Schwarz, Jesper; Brown, Liam; van den Berg, Ashmiani; Amabilino, David B.

Abstract

The alkylation of 1,4-diketo-3,6-arylpyrrolo[3,4-c]pyrroles (ArDPP) is one of the most important steps in the synthesis of soluble materials based on these molecules and the polymers derived from them (that are employed widely in putative organic solar cells). Here we report an improvement in their method of synthesis replacing habitual solvent and base. Compared with more usual conditions, we employed acetonitrile as solvent to give higher or similar yields, with less toxic and hazardous waste, lower reaction time and temperature, and allows recycling of unreacted starting materials. Unlike dimethylformamide and N-methylpyrrolidone, which are the most commonly employed solvents. Our reaction conditions have been tested on three different ArDPPs (Ar = thiophene, phenyl and 4-methoxyphenyl) with a variety of linear and branched alkyl reagents. The results show similar and improved results in comparison with the published reports while reducing the waste and hazard of the reaction, as well as simplifying the purification of the products in many cases. Overall this method has lower environmental impact, is more cost effective and requires neither the use of dry solvent nor inert atmosphere.

Citation

Pop, F., Humphreys, J., Schwarz, J., Brown, L., van den Berg, A., & Amabilino, D. B. (2019). Towards more sustainable synthesis of diketopyrrolopyrroles. New Journal of Chemistry, 43(15), 5783-5790. https://doi.org/10.1039/c9nj01074b

• Journal Article Type: Article
• Acceptance Date: Mar 14, 2019
• Online Publication Date: Mar 20, 2019
• Publication Date: Mar 20, 2019
• Deposit Date: Mar 21, 2019
• Publicly Available Date: Mar 21, 2020
• Journal: New Journal of Chemistry
• Print ISSN: 1144-0546
• Electronic ISSN: 1369-9261
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 43
• Issue: 15
• Pages: 5783-5790
• DOI: https://doi.org/10.1039/c9nj01074b
• Keywords: Materials chemistry; General chemistry; Catalysis
• Public URL: https://nottingham-repository.worktribe.com/output/1673601
• Publisher URL: https://pubs.rsc.org/en/Content/ArticleLanding/2019/NJ/C9NJ01074B#!divAbstract
• Contract Date: Mar 25, 2019