This observation prompted us to explore the reactivity of DBU in organic synthesis for esterfication. In continuation of our work of synthesis of Chain Transfer Agents for RAFT polymerization, herein we wish to report a new method for the synthesis of ester containing the trithiocarbonate and dithio ester using acid and alkyl bromide, iodide and mesiylate in presence of DBU in DMSO at ambient temperature. Propargyl esters 3a, 4a , azido esters 3b, 4c , 5c and borate ester 3e, 4e and 4f were successfully prepared and characterized. Propargyl esters and azido esters were used in click chemistry for getting graft polymer intermediates. In a direct attempt to prepare 2d from 3-azido-1-propanol with phosphorous tribromide in ether gives impurities, may be azido is some affinity towards the phosphorous tribromide, but in a stepwise synthesis from 3-azido-1-propanol is feasible. Thus the 3-azido-1-propanol was converted to corresponding mesylate In an attempt to convert the diacid 1a to diacid chloride 6 by using thionyl chloride, isolated complex structure in quantitative yield instead of expected product. In another attempt with oxalyl chloride at temperature for 2 hours rearranged product, thioepoxide-monoacid chloride 7