Alternative methods for obtaining of cherylline derivatives

In this book are presented the results from research on alternative approaches towards the synthesis of 4- aryl-l,2,3,4-tetrhydroisoquinolines as synthetic analogues of the alkaloid cherylline. Optimal conditions for the synthesis of the required 2,2-disubstituted ethylamine precursors are found. The Schotten- Baumann method for amide synthesis is then successfully applied and the synthesized amides are used in an intramolecular -amidoalkylation reaction to obtain 4-substituted 1,2,3,4-tetrahydroisoquinolines. An eco-friendly procedure utilizing PPA/SiO2 catalyst for the intramolecular -amidoalkylation is developed. Microwave-assisted variant of this eco-friendly procedure is also successfully developed. By the Bischler-Napieralski method are synthesized five new 1,4- disubstituted-l,2,3,4-tetrahydroisoquinolines. These are potential inhibitors of DHODH. It is found that the reduction of 1,4-disubstituted 3,4-dihydroisoquinolines leads to formation of diastereoisomers. The diastereoisomers are successfully separated by preparative column chromatography and 2:1 (cis:trans) ratio is determined. This ratio is not affected by the temperature at which the reaction is carried out.

Autorentext

Stanimir Manolov received his B.Sc. of Computer chemistry (2008), M.Sc. (2009), and Ph.D. of Organic chemistry (2015) degrees from University of Plovdiv (Bulgaria). His research in the group of Prof. Iliyan Ivanov is focused on the development of new synthetic methodologies of biologically active natural compounds.