Fluorinated phosphorus compounds Part 10.Bis(fluoroalkyl) S-alkyl phosphorothiolates and tris(fluoroalkyl) phosphorothionates

摘要

Treatment of bis(fluoroalkyl) phosphites (R_FCH_2O)_2P(O)H,where R_F was CF_3 or C_2F_5 with sulfur in pyridine at 80degC gave salts of structure [(R_FCH_2O)_2P(O)SH]NC_5H_5 in 90 and 88% yield,respectively.The salts reacted with alkyl iodides in acetonitrile at 50degC to furnish bis(fluoroalkyl) S-alkyl phosphorothiolates (R_FCH_2O)_2P(O)SR,where R was Me,Et,n- and i-Pr (when R_F=CF_3) and Me (when R_F=C_2F_5).Yields ranged from 21 to 57%.Bis(trifluoroethyl) S-methyl phosphorothiolate (CF_3CH_2O)_2P(O)SMe underwent fluorination by silver fluoride in acetonitrile at room temperature to yield the phosphorofluoridate (CF_3CH_2O)_2P(O)F in 75% yield.Tris(fluoroalkyl) phosphorothionates (R_FCH_2O)_3P=S,where R_F was CF_3,C_2F_5 and C_3F_7,were prepared in 30-34% yield by heating the tris(fluoroalkyl) phosphites (R_FCH_2O)_3P and sulfur to 200degC in a sealed tube for 8 h.