2386-37-0Relevant academic research and scientific papers
Process For Preparing Porphyrin Derivatives, Such As Protoporphyrin (IX) And Synthesis Intermediates
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Page/Page column 15, (2008/12/07)
The present invention relates to a process for preparing a porphyrin of formula (I), optionally in the form of a salt with an alkali metal and/or in the form of a metal complex: in which: R and R′ are as defined in claim 1, comprising: a step of condensation, in an acidic medium, between a dipyrromethane of formula (II): in which R′b is as defined above for (I), and a dipyrromethane of formula (III): in which R″ is as defined in claim 1, and also the compounds of formula (III).
Synthesis of cyanopyrroles
Cheng, Lingjiang,Lightner, David A.
, p. 46 - 48 (2007/10/03)
Regioselective synthesis of α-cyanopyrroles (vs. α- alkoxycarbonylpyrroles) using oximinocyanoacetate esters in a Knorr-type reductive condensation with β-diketones can be directed by the presence of water. Thus, methyl oximinocyanoacetate was reacted with pentane-2,4-dione in hot acetic acid in the presence of zinc dust to give exclusively 3,5- dimethylpyrrole-2-carbonitrile when the acetic acid was wet; whereas, in glacial acetic acid only methyl 3,5-dimethylpyrrole-2-carboxylate was isolated (~40% yield).
Thermochemistry of substituted pyrroles
Berezin, M. V.,Semeikin, A. S.,V'yugin, A. I.,Krestov, G. A.
, p. 449 - 453 (2007/10/02)
The heats of solution of a series of substituted pyrroles in benzene, carbon tetrachloride, chloroform, DMF, and pyridine were measured by a calorimetric method at 298.15 K.The influence of substituents in the pyrrole molecule on the energy parameters of solvation by organic solvents is discussed.
Some Mercuration Reactions of Substituted Pyrroles
Ganske, Jane A.,Pandey, Ravindra K.,Postich, Michael J.,Snow, Kevin M.,Smith, Kevin M.
, p. 4801 - 4807 (2007/10/02)
Mercuration of N-unsubstituted pyrroles with mercury(II)acetate results in immediate precipitation of the N-mercurated derivative, which is insoluble in virtually all organic solvents.If the pyrrole N atom is protected (e.g.with Me, CH2OCH2Ph, or CO2t-Bu)
Pyrrole Chemistry. An Improved Synthesis of Ethyl Pyrrole-2-carboxylate Esters from Diethyl Aminomalonate
Paine, John B.,Dolphin, David
, p. 5598 - 5604 (2007/10/02)
Ethyl pyrrole-2-carboxylates, versatile precursors for the total synthesis of both synthetic model and naturally occurring tetrapyrroles and porphyrins, can be prepared in greatly improved yields by the addition of 1,3-diketones and preformed diethyl aminomalonate to boiling glacial acetic acid.The method is suitable for both small- and large-scale synthesis and has proved far more reliable than the original in situ dissolving zinc reduction of diethyl oximinomalonate discovered by Kleinspehn.Yields range from 60-70percent for the dominant product isomer from unsymmetrical diketones to 75-90percent for the single product derived from symmetrical diketones.Seventeen examples of alkyl-substituted ethyl pyrrole-2-carboxylates are provided.Improved procedures are given for the preparation of the required precursors.
