Photocyclisations of some 3‐alkoxy‐2‐thienylchromones

Photoreorganisations of some 3‐allyloxy‐2‐thienylchromones have been described. The photoreactions are initiated through the intramolecular H‐abstraction to provide angular tetracyclic compounds. These chromones yield good chemical efficiency due to the involvement of highly stabilized allylic 1,4‐biradicals.     

Convenient way to 5‐substituted 4‐amino‐2,3‐dihydro‐4H‐1,2,4‐triazole‐3‐thiones

Various 4‐amino‐2,3‐dihydro‐4H‐triazoles with aromatic, aliphatic and heterocyclic substituents at the C(5) position were synthesized from corresponding esters and thiocarbohydrazide. This method allows the synthesis these heterocycles in a short time and at reduced expenses.     

Studies with enaminones: Formation of a N,O‐cyclicacetal on coupling of 3‐dimethylamino‐1‐hydroxyphenyl‐2‐propenone with arenediazonium salts

Coupling the title compound 3 with arenediazonium salts affords the arylhydrazonochromones 6 . The latter compounds react with hydrazine hydrate to yield novel pyrazoles 11 .     

Synthetic and spectroscopic studies of some new 2‐[1‐aryl‐4{4‐methoxyphenyl}‐6‐thioxo‐1,6‐dihydro‐1,3,5‐triazinyl]amino/hydrazonothiazolidin‐4‐ones

A series of 4‐thiazolidinones having triazinethione moieties have been synthesized by the systematic chemical modification of S‐benzylmercapto‐1‐aryl‐4‐(4‐methoxyphenyl)‐1,6‐dihydro‐1,3,5‐triazine‐6‐thione.     

Synthesis and antimalarial activity of 7‐benzylamino‐1‐isoquinolinamines

Computer modelling suggests that 7‐benzylamino‐1‐isoquinolinamines should mediate antimalarial effects by a mechanism distinct from that employed by existing antimalarial drugs. A series of these compounds was prepared in seven synthetic steps, via reductive amination of 1,7‐isoquinolinediamine. In vitro efficacy testing of the novel compounds against Plasmodium falciparum revealed them to be potent antimalarial agents.