Structure Based Library Approach to Photosynthesis Inhibitors:The Solid Phase Synthesis of Hydro-Uracils and Thiouracils

A general method for the solid phase synthesis of hydro-uracils and thiouracils is described. Resino ester 2 reacts with various primary amines to give secondary amines 3, which are converted to the resino ureas (thioureas) 4 by treatment with isocyanates (isothiocyanates). Preparation of the hydro-uracils and thiouracils 5 is achieved by acidic cyclization-cleavage from the resin. The synthesis is designed to be amenable for structure based library approach to photosystem II D1 protein inhibitors.

Studies on the reaction of 3-substituted-4-hydroxy-2H-1,2-benzothiazine 1,1-dioxides with aryl isocyanates and the synthesis of corresponding derivatives

The reaction of 3-substituted-4-hydroxy-2H-1,2-benzothiazine 1,1-dioxides with aryl isocyanate under different equivalents of strong base NaH was studied. Seventeen of new derivatives were obtained whose structures were characterized by H-1 NMR, IR, MS, elementary analysis and FeCl3 test.