Reactions of polyfluoroaromatic imidoyl chloride derivatives with S-nucleophilic reagents

Abstract

The interactions of N-pentafluorophenylcarbonimidoyl dichloride, N-pentafluorophenylbenzimidoyl chloride and N-pentafluorophenyl (C-pentafluorophenyl) imidoyl chloride with the S-nucleophilic reagents thiourea, sodium N,N-diethyldithiocarbamate, thiocarbonyl difluoride and bis(trifluoromethyl)trithiocarbonate in the presence of CsF or AgSCF 3, or thiophenol and polyfluorinated thiophenols in the presence of anhydrous K 2CO 3, were studied. Reactions with charged S-nucleophiles and with S-nucleophiles in the presence of a base proceeded with preservation of the N-C multiple bond in the reaction products. By varying the reaction conditions in the case of N-pentafluorophenylcar-bonimidoyl dichloride it was possible to substitute one or two chlorines and obtain mono- or di-thioimidates. When C 6F 5 or SC 6F 5 groups were present at the C atom of the N-C multiple bond, preferential substitution of the para-fluorine atom occurred. Semiempirical PM3 calculation data were used to explain the direction of these reactions. N-Pentafluorophenylcarbonimidoyl dichloride reacted with sodium N, N-diethyldithiocarbamate or thiourea to give pentafluorophenylisothiocyanate. Depending on the conditions of the reactions of polyfluorinated benzimidoyl chlorides with thiourea, N-pentafluorophenylthioamides and 2-aryl-4,5,6,7-tetrafluorobenzothiazoles were formed. An attempt to produce SCF 3 derivatives from AgSCF 3 was unsuccessful.