7509-11-7Relevant articles and documents
A switchable oxidation process leading to two various versatile pharmaceutical intermediates
Occhipinti, Giovanni,Liguori, Lucia,Tsoukala, Anna,Bjorsvik, Hans-Rene
supporting information; experimental part, p. 1379 - 1384 (2011/09/20)
An efficient high-yielding and environmentally benign switchable oxidation process that can selectively produce two different versatile synthetic intermediates is disclosed. One of the two intermediates, 2,3-dimethoxy-5- methylcyclohexa-2,5-diene-1,4-dione (coenzyme Q0), is obtained by means of a telescoped two-step synthetic protocol that in the first step involves treatment of the substrate (1,2,3-trimethoxy-5-methylbenzene) with hydrogen peroxide in acetic acid with p-toluene sulphonic acid present as a Bronsted acid catalyst, succeeded by a telescoped second step that entails treatment with fuming nitric acid to achieve the target molecule in an excellent isolated yield (88%). If the substrate is treated directly with nitric acid (65%) in glacial acetic acid two different products can be obtained, namely acetic acid 3,4,5-trimethoxybenzyl ester in a superb isolated yield (93%) or, under slightly altered reaction conditions, 1,2,3-trimethoxy-5- (nitromethyl)benzene in a moderate to low yield (35%) and low selectivity. The two pathways leading to the two different products in the nitric acid oxidation protocol were investigated by means of DFT calculations as an aid to elaborate a proposal for the reaction mechanism.
Synthesis of 6-methyl-8H-dibenzo[a,g]quinolizin-8-imines via Reissert compounds
Reimann, Eberhard,Hertel, Rainer,Krauss, Juergen
experimental part, p. 673 - 684 (2009/07/18)
Alkylation of Reissert compounds derived from 3-methylisoquinolines with several 2-cyanobenzylbromides followed by hydrolytic cleavage provided the corresponding 1-benzyl-3-methylisoquinolines. Treatment of the latter with methylmagnesiumiodide caused cyclization to the title compounds rather than formation of 2-acetylbenzylisoquinolines.
Structural requirements for ipso-nitration with cerium(IV) ammonium nitrate (CAN)
Asghedom,LaLonde,Ramdayal
, p. 3989 - 3991 (2007/10/03)
Compounds in which the carbon skeleton contains at least a diarylmethane with the aromatic rings appropriately substituted by electron donating groups exhibited ipso-nitration when treated with cerium(IV) ammonium nitrate (CAN).
Effects of superoxide anion generated from aromatic radical anions produced in nucleophilic aromatic photosubstitution reactions
Cervera, Maria,Marquet, Jordi
, p. 966 - 969 (2007/10/03)
Superoxide anion is generated from aromatic radical anions produced in nucleophilic aromatic photosubstitutions when the reactions are carried out in non-deoxygenated solutions of polar aprotic solvents. Superoxide anion thus generated displaces cyanide anion from acetonitrile and benzyl cyanide, ethoxide anion from ethyl acetate, and methanesulfenate anion from dimethyl sulfoxide. Hence, non-deoxygenated polar aprotic solvents should be avoided in nucleophilic aromatic photosubstitution reactions.