Molecules 2006-01-01

Synthesis of new trans-2-benzyl-3-(furan-2-yl)-4-substituted-1,2,3,4-tetrahydroisoquinolinones.

Meglena I Kandinska, Ivan D Kozekov, Mariana D Palamareva

Index: Molecules 11(6) , 403-14, (2006)

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Abstract

The reaction of homophthalic anhydride and N-(furan-2-yl-methylidene)- benzylamine in different solvents and varying temperatures was studied in detail. Mixtures of the expected trans- and cis-1,2,3,4-tetrahydroisoquinoline-4-carboxylic acids trans-5 and cis-5, along with by-products 6 and 7 were obtained in dichloroethane or benzene. In pyridine, used for the first time, the reaction became completely diastereoselective, giving only the trans isomer. The carboxylic acid group of trans-5 was transformed in four steps into cyclic aminomethyl groups which yielded various new tetrahydroisoquinolinones trans- 11a-g, incorporating both a known fragment of pharmacological interest and various pharmacophoric substituents.