engleski

An Unusual Case of Carbon-Nitrogen Bond Formation. Reactivity of C-nitroso Group Toward Acyl Chlorides

Acyl chlorides react with nitrosobenzene in 99.9 % acetonitrile and in presence of the catalytic amounts of HCl giving the corresponding N-p-chlorophenyl hydroxamic acids. Under the conditions employed in the kinetic investigation the reaction goes to completion, as evidenced spectroscopically. Kinetic evidence obtained is consistent with the rate law: rate=k1[HCl]2[Ph-NO] + k2[HCl][Ph-NO], (Ph-NO = nitrosobenzene) The rate constants observed for the formation of hydroxamic acid do not depend on the acyl chloride concentration, but are linearly dependent on the added chloride (benzyltrimethylammonium chloride) concentration. Solvent kinetic isotope effect (KIE) kDCl/kHCl between DCl and HCl of 1.23 was observed. Substrate KIE between nitrosobenzene and nitrosobenzene-d5, kH/kD of 1.25 was also observed. These and other results are consistent with the formation of intermediates (4) and (5) and the rapid interaction of the intermediates with acyl chloride, followed by the proton transfer from C-4 of nitrosobenzene and the formation of product hydroxamic acid.

nije evidentirano

nije evidentirano