Synthesis and Biological Evaluation of 3-cyano-4H-chromene Derivatives Bearing Carbamate Functionality.

Background: 2-Aminochromene derivatives display important pharmacological properties, including mainly antibiotic and anticancer activities.

Objective: The study aims to synthesize new chromene derivatives via a new approach using Grignard reagents, for the evaluation of their antibiotic and antifungal properties.

Method: A series of novel 3-cyano-4-aminochromene derivatives bearing alkyl substituents at the 4-position was prepared for biological evaluation.

Successive addition of two different Grignard reagents to nitriles: access to α,α-disubstituted propargylamine derivatives.

The successive addition of two different Grignard reagents to acyl cyanohydrins was performed with success by taking advantage of the low reactivity of alkynyl Grignard reagents. The experimental conditions were adjusted so that they were not reactive during the first addition step, but reactive only in the second one. The synthetic utility of the prepared compounds was validated by the preparation of chiral quaternary α-amino acids.

Cyclopropyl-tryptamine analogues: synthesis and biological evaluation as 5-HT(6) receptor ligands.

Conformational restrictions: Based on the pharmacophore model for 5-HT(6) receptor ligands (shown), tryptamine analogues bearing a cyclopropyl ring on the α-position of the tryptamine side chain were synthesized and evaluated against 5-HT receptors. N,N-Dimethyl-1-arylsulfonyltryptamine derivatives exhibited promising selectivity for 5-HT(6) over 5-HT(1a) and 5-HT(4) receptors and interesting activity against 5-HT(6) (K(i) =∼0.15 μM; IC(50) =∼0.

Simple and convenient access to α,α,α-trisubstituted amides by double addition of Grignard reagents to acyl cyanohydrins.

The double addition of Grignard (alkyl, aryl, alkenyl, alkynyl) reagents to acyl cyanohydrins was performed under unusually smooth conditions with a concomitant O-N acyl transfer, providing a very simple and general access to α,α,α-trisubstituted amides.