Green technology towards pharmaceutical drug development: I. Synthesis of differentially functionalized hydroquinone as an important pharmaceutical intermediate. II. Application in green chemistry: Environmentally friendly cleavage of aromatic ethers and trans-etherification under neutral conditions. III. Environmentally friendly simple amidation of nitro compounds: One step synthesis of acetaminophen.

摘要

This thesis is divided into three separate parts. In first part, a full scale synthesis and process development of 4-(2-Bromoethoxy)phenol is described. Dakin reaction conditions was developed for the synthesis of 4-(2-Bromoethoxy)phenol. Yield was improved from 35% to 65% over the two steps. Dakin oxidation condition was found equally suitable for electron rich aromatic aldehydes as well as electron poor aromatic aldehydes.; In second part, a simple, efficient, solvent free cleavage of electron poor aryl ethers and subsequent trans-etherification under essentially neutral conditions is described. Regioselective aryl methoxy cleavage exploiting differential reactivity towards nucleophiles was achieved. The fact that the reactions proceed to high conversions, selectivity and vessel efficiency renders the process practical and economically attractive and demonstrates the utility of the surfactant mediated solvent free technology in organic synthesis.; In third part, one-step, one-pot, solvent free reductive amidation of the nitroarenes under neutral conditions is described. Various nitroarenes has been converted to the corresponding N-arylacetamides which shows the generality of this novel methodology. This methodology can be applicable to the synthesis of various heterocycles including thiazole, oxazole, and amidazole.