34259-29-5Relevant articles and documents
Chemistry of diazocarbonyl compounds: XXVIII. Reaction of acyclic N-arylsulfonylacetamides with Rh(II)-carbenoids as a new synthetic route to alkyl acetimidoates
Selivanova,Nikolaev,Kostikov,Nikolaev,Siler,Schulze
, p. 1792 - 1799 (2007/10/03)
A new procedure was proposed for the synthesis of alkyl acetimidoates via alkylation of the carbonyl group in N-arylsulfonylacetamides with Rh(II)-carbenoids. The procedure ensures preparation in good yield of acetimidoates having a polyfunctionalized O-alkyl group. The obtained alkyl acetimidoates in crystal exist as E isomers with respect to the C=N bond and as s-cis conformers relative to the C-OCHRR' bond. Alkyl N- arylsulfonylacetimidoates react with ammonia and hydrazine hydrate to give in good yield the corresponding carboximidamides(hydrazides) via replacement of the O-alkyl group. Unlike structurally related compounds having simple alkyl or aryl groups on the nitrogen atom, N-arylsulfonylacetimidoates readily undergo hydrolysis in the presence of moisture and traces of acids.
Kinetics and Mechanism of Oxidation of Dimethyl Malonate by Chromic Acid in Presence and in Absence of Manganous Ions
Oswal, S. L.
, p. 738 - 742 (2007/10/02)
The kinetics of the chromic acid oxidation of dimethyl malonate in acetic acid-water solutions of H2SO4-H3PO4 in the presence and in absence of manganous ions have been studied at constant ionic strength, at different temperatures in the range 303-328 K and at various in the range 0.75-1.5 mol dm-3.A well defined induction period is observed.MnII ion markedly catalyses the oxidation of dimethyl malonate by chromic acid which have low activation energy.The catalysis is ascribed to the reaction, followed by a slow oxidative break down of the MnIII complex, producing free radical and MnII.Catalysis by MnII reached an upper limit when the maximum concentration of complexed ion formed.The special kinetic features of uncatalysed oxidations disappear, i.e. uncatalysed oxidation is dependent on total VI> while catalysed on fraction of ->.Energy, free energy and entropy of activation for uncatalysed reaction are 61.5 kJ mol-1, 98.7 kJ mol-1 and -117.1 J mol-1 K-1, and for catalysed reaction the values are 48.9, 80.7 and 104.6, respectively.
