Kinetics and Mechanisms of the Reaction of para-Chlorophenyl Aryl Chlorothiophosphates with Anilines in Acetonitrile at 55℃.

초록

The kinetics and mechanism of the aminolysis of para-chlorophenyl aryl chlorothiophosphates, (p-CIC6H4OP(=S)(CI)OC6H4Y) 1, have been carried out in acetonitrile at 55℃. The obtained second-order rates for Y= p-CI, X=H (pKa = 3.98), k2 = 3.00X10-4 M-1s-1 at 55℃ in 1, Y=m-CI,), k2= 14.1X10-4 M-1 s-1 at 55℃ in para-chlorophenyl aryl chlorophosphates, ( p-CIC6H4OP(=O)(CI)OC6H4Y, Y=m-CI, X=H, pKa=3.52)2, and k2 = 1.80X10-4 M-1 s-1 at 55℃ in aryl phenyl chlorothiophosphates, (C6H4Y, Y=m-CL, X=H, pKa=3.52) 3. The rates are much slower than those for corresponding reactions of 2, due to lower electrophilicity of P in P=S relative to P=O. The rates are faster than than those for for the corresponding reactions of 3. The magnitudes og pX=-3.87 ± 0.33 (r=0.993), βX= 1.37 ± 0.10 (r=0.993) (Y=p-CI) of 1 are both slightly smaller than 2 and similar to 3.