title: A p-methoxybenzyl (PMB) protection/deprotection approach toward the synthesis of 5-phenoxy-4-chloro-N-(aryl/alkyl) thiophene-2-sulfonamides.
abstract: The synthesis of 17 phenoxy substituted 4-chloro-N-(aryl/alkyl)thiophene-2-sulfonamides using a PMB protection/deprotection strategy is described. Nucleophilic displacement of p-methoxybenzyl (PMB) protected 4,5-dichloro-N-(aryl/alkyl)-thiophene-2-sulfonamides was carried out with different phenols under mild basic conditions. Reaction times of 3-6 h and overall yields of 78-98% were achieved with the PMB group in place compared to no reaction without this protecting group. The PMB group was easily and selectively removed in 68-98% yield using TFA in DCM.
authors: Department of Pharmaceutical Sciences, Biomanufacturing Research Institute and Technology Enterprise (BRITE), North Carolina Central University, Durham, NC 27707, USA. awilliams@nccu.edu
authors: Alfred L
authors: AL
authors: Williams
authors: Srinivasa R
authors: SR
authors: Dandepally
authors: Sharadsrikar V
authors: SV
authors: Kotturi
mesh_terms: D002626:Chemistry, Pharmaceutical / Q000379:methods*; D004121:Dimethyl Sulfoxide / Q000737:chemistry / Q000494:pharmacology; D004126:Dimethylformamide / Q000737:chemistry / Q000494:pharmacology; D004146:Dioxanes / Q000737:chemistry / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D008954:Models, Biological; D015394:Molecular Structure; D013449:Sulfonamides / Q000138:chemical synthesis* / Q000737:chemistry; D013696:Temperature; D013876:Thiophenes / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D004146:Dioxanes; D013449:Sulfonamides; D013876:Thiophenes; D004126:Dimethylformamide; C025223:1,4-dioxane; D004121:Dimethyl Sulfoxide