STUDIES OF REACTIONS OF DIMETHYLPHOSPHORAMIDIC DIFLUORIDE WITH TRANS-2-(N,N-DIALKYLAMINO)CYCLOALKANOLS IN THE PRESENCE OF VARIOUS SULFUR-CONTAINING NUCLEOPHILES

The reactions of dimethylphosphoramidic difluoride (I) with trans-2-(N ,N-dialkylamino)cycloalkanols were studied in the presence of various sulfur-containing nucleophiles and Et3N. When O,O-diisopropyl thiophos phoric acid was used as a nucleophile, the corresponding O, O-diisopro pyl S-[2-(N,N-dialkylamino)cycloalkyl] thiophosphates were obtained in satisfactory yields. The direction of this reaction in the presence o f O-isopropyl toluenephosphonothioic acid depends on the pK(a) of amin oalcohol, namely, the amount of O-isopropyl tolylphosphonofluoridate t hat was formed along with O-isopropyl S-[2-(N,N-dialkylamino)cycloalky l] tolylphosphonothioates was increased as the pK(a) increased. The re actions of compound 1 with trans-2-(N, N-dialkylamino)cycloalkanols an d thioacetic acid afforded 2-(N,N-dialkylamino)cycloalkanethiols, cert ain of which were readily oxidized to the corresponding disulfides. In the case of potassium ethyl xanthate, the composition of the reaction products depends on the nature of aminoalcohol. X-ray diffraction ana lysis of S-(2-piperidinocyclohexyl) N,N-dimethyldithiocarbamate demons trated that this compound exists as the trans isomer. This fact suppor ts the reaction mechanism, which we have suggested previously and whic h involves the formation of aziridinium cations followed by their open ing under the action of nucleophilic agents.