Reference of 133228-21-4,Some common heterocyclic compound, 133228-21-4, name is N,N-Dimethyl-1H-pyrazole-1-sulfonamide, molecular formula is C5H9N3O2S, traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route.
Step A: Preparation of 3~bromo-N,N-dimethyl-lH-pyrazole-l-sulfonamide; To a solution of N,N-dimethylsulfamoylpyrazole (44.O g, 0.251 mol) in dry tetrahydrofuran (500 mL) at -78 0C was added dropwise a solution of n-butyllithium (2.5 M in hexane, 105.5 mL, 0.264 mol) while maintaining the temperature below -60 C. A thick solid formed during the addition. Upon completion of the addition the reaction mixture was stirred at -78 C for an additional 15 minutes, after which time a solution of 1,2-dibromo- tetrachloroethane (90 g, 0.276 mol) in tetrahydrofuran (150 mL) was added dropwise while maintaining the temperature below -70 0C. The reaction mixture turned a clear orange; stirring was continued for an additional 15 minutes. The -78 0C bath was removed and the reaction was quenched with water (600 mL). The reaction mixture was extracted with methylene chloride (4x), and the organic extracts were dried over magnesium sulfate and concentrated. The crude product was further purified by chromatography on silica gel using methylene chloride-hexane (50:50) as eluent to afford 57.04 g of the title product as clear colorless oil. 1H NuMR (CDCl3): delta 7.62 (m,lH), 6.44 (m,lH), 3.07 (d,6H).
The synthetic route of 133228-21-4 has been constantly updated, and we look forward to future research findings.
Reference:
Patent; E.I. DUPONT DE NEMOURS AND COMPANY; WO2006/68669; (2006); A1;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics