Synthesis and Structure of 4-Trifluoromethylsulfonamidotrichloroethyl-5-chloropyrazoles

Abstract

Reactions of trifluoromethanesulfonic acid N-(2,2,2-trichloroethylidene)amide with 1,3-dialkyl-5chloropyrazoles and 1-phenyl-3-methylpyrazole afforded 4-(amidotrichloroethyl)-substituted pyrazole derivatives. 4-Chloropyrazoles were not involved into this process. The structure of compounds synthesized was studied by means of IR and NMR spectroscopy. The presence of intra-and intermolecular hydrogen bonds was revealed by a decrease in the absorption frequencies and a complicated form of n(NH) and n as (SO 2 ) absorption bands in the IR spectra, and also in splitting of signals in 1 H and 13 C NMR spectra.

Trifluoromethanesulfonamides and Related Compounds

“…In a series of works, Rozentsveig et al have shown it to react with 1,2-dichloroethylene, − trichloroethylene, , and vinylidene chloride to give CF 3 SO 2 NCHCHCl 2 , CF 3 SO 2 NCHCCl 3 , and CF 3 SO 2 NHCH 2 CCl 3 , respectively. A highly electrophilic CN bond adds various O- (water, methanol, p -nitrophenol), N- (PhSO 2 NH 2 , triflamide, acrylamide), and C-nucleophiles (phenol, thiophene, indoles, pyrazoles). − With tribromoethylene, depending on the reaction conditions, N , N -dichlorotriflamide gives either CF 3 SO 2 NCHCBr 2 Cl (at <40 °C) or its 1:1 mixture with CF 3 SO 2 NCHCBr 3 (when the reaction mixture is allowed to warm up to 100 °C) …”

10.1007/s11178-008-1010-2

“…According to our previous data [4,11], N-(2,2,2-trichloroethylidene)trifluoromethanesulfonamide (IIa) is more reactive than analogous N-substituted arenesulfonamides toward nucleophiles, as well as in C-amidoalkylation of arenes and hetarenes. The reactions of IIa-IIe with indoles IIIa-IIIe required neither catalyst nor elevated temperature and were accompanied by heat evolution.…”