Rates of Reaction of Vicinally Substituted Hydroxamic Acids with

~ I A R V 'I1K . STOLBERG A N D ~TILLIAX A. ~ I O S H E R

"1s [CONTRIBUTION FROX

THE

IFol. 79

CHEMOTHERAPY BRANCH, CHEMICAL WARFARELABORATORIES, AND

THE

DEPARTMENT OF

CHEMISTRY O F THE UNIVERSITV OF DELAlVARE]

Rates of Reaction of Vicinally Substituted Hydroxamic Acids with Isopropyl Methylphosphono fluoridate (Sarin) Br MARVIN A. STOLBERG? AXD I~-ILLIAII A.;LIOSHEK RECEIVED JULY 17, 1956 'l'he hdlf-time of hydrolysis, pseudo-iiio~iotiiolecularrate constants and the specific rate coxistarits for the reaction of certain +substituted benzohydroxamic and vicinal dihydroxamic acids with isopropyl methylphosphonofluoridate (Sarin) are reported. h plot of the log," of the specific rate constants veysus the pK,'s of the hydroxamic acids coincided with the line previously established for the p-substituted benzohydroxamic acids. Thus, there is no marked change of the rates of reaction of hydroxamic acids with Sarin due to vicinal substitution and no alteration in the nature of the reacting group by these substituents. T h e most probable reactive form of the hydroxamate ion is postulated.

,In exhaustive investigation of the Lossen rearrangement of acylated hydroxamic acids has been reported by Hauser and associate^.^ It was shown that the rates of decomposition of the potassium salts of a series of dibenzohydroxamates

i n which K is phenyl and I