Ill Young Lee

Solid-phase synthesis of thiazolo[4,5-b]pyridine derivatives using Friedländer reaction.

Traceless solid-phase synthesis of 2,5,6,7-tetrasubstituted thiazolo[4,5-b]pyridine derivatives is described. Thorpe-Ziegler type cyclization of solid supported cyanocarbonimidodithioate with alpha-halo ketones afforded thiazole resin, which were converted to the desired thiazolopyridine resin by the Friedländer protocol under microwave irradiation conditions. After oxidation of sulfides to sulfones, nucleophilic desulfonative substitution with amines gave the target thiazolo[4,5-b]pyridine derivatives in good overall yields.

APPROXIMATE RATE CONSTANTS FOR INTERMOLECULAR ADDITIONS OF ALKYL RADICALS TO PHENYLSULFONYL OXIME ETHERS

Abstract Approximate rate constants for intermolecular additions of alkyl radicals to phenylsulfonyl oxime ethers ( 2a and 2b ) have been determined to be k a =9.6×10 5 M −1 s −1 at 25 °C for 2a and k a =7.3×10 4 M −1 s −1 at 60 °C for 2b , indicating that the additions are fast and highly efficient processes. The kinetic data have been confirmed by two competition experiments.