Water mediated construction of trisubstituted pyrazoles/isoxazoles library using ketene dithioacetals.
A small molecule library of alkyl, sulfone, and carboxamide functionalized pyrazoles and isoxazoles has been developed via a rapid sequential condensation of various alpha-acylketene dithioacetals (1a-o) with hydrazine hydrate or hydroxylamine hydrochloride, followed by oxidation of sulfide to sulfone using water as the reaction medium. An efficient and safe oxidation of sulfides (4/5a-o) to the corresponding sulfones (6/7a-o) using sodium per borate system in aqueous medium is reported. The concise and two step synthesis of trisubstituted pyrazoles and isoxazoles was investigated under variety of reaction condition. The newly developed methodology has the advantage of excellent yield and chemical purity with short reaction time using water as a solvent.
Savant
Mahesh M
MM
Department of Chemistry, Chemical Research Laboratory, Saurashtra University, Rajkot, India.
Pansuriya
Akshay M
AM
Bhuva
Chirag V
CV
Kapuriya
Naval
N
Patel
Anil S
AS
Audichya
Vipul B
VB
Pipaliya
Piyush V
PV
Naliapara
Yogesh T
YT
D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000138:chemical synthesis; D020650:Combinatorial Chemistry Techniques / Q000379:methods*; D052246:Cyclooxygenase 2 Inhibitors / Q000138:chemical synthesis / Q000737:chemistry; D005030:Ethylenes / Q000737:chemistry*; D007555:Isoxazoles / Q000138:chemical synthesis* / Q000737:chemistry; D007659:Ketones / Q000737:chemistry*; D007783:Lactones / Q000138:chemical synthesis / Q000737:chemistry; D015394:Molecular Structure; D010068:Oxacillin / Q000138:chemical synthesis / Q000737:chemistry; D010084:Oxidation-Reduction; D011720:Pyrazoles / Q000138:chemical synthesis* / Q000737:chemistry; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D013450:Sulfones / Q000138:chemical synthesis / Q000737:chemistry; D014867:Water / Q000737:chemistry*
D000900:Anti-Bacterial Agents; D000894:Anti-Inflammatory Agents, Non-Steroidal; D052246:Cyclooxygenase 2 Inhibitors; D005030:Ethylenes; D007555:Isoxazoles; D007659:Ketones; D007783:Lactones; D011720:Pyrazoles; D013438:Sulfhydryl Compounds; D013450:Sulfones; D014867:Water; C116926:rofecoxib; C008223:ketene; D010068:Oxacillin