16200-50-3Relevant articles and documents
Reduction of acyl pyrrole esters by zinc-hydrochloric acid
Cheng,Ma
, p. 2771 - 2775 (1994)
The pyrryl alkyl ketone and acetylpyrrole esters were reduced to corresponding alkylpyrrole esters by zinc-hydrochloric acid in alcohol in high yields (> 90%).
2,3-Diazaporphyrins Bearing Two Nitrogen Atoms at the Periphery
Boehme, Roswitha,Breitmaier, Eberhard
, p. 2096 - 2102 (2007/10/03)
The first synthesis of 2,3-diazaporphyrins 3 bearing two nitrogen atoms at peripheral positions from tripyrranes 1, prepared in situ by mild acidolysis and decarboxylation of the di-t-butyldicarboxylates, and 4H-1,2,4-triazol-3,5-dicarbaldehyde (2) is described, using the [3+1] principle of porphyrine cyclization. Similar to the parent porphyrins, the new diazaporphyrins 3 exhibit significantly shielded inner protons, reflecting the ring current of an 18 ? aromatic system and Soret bands in the UV-vis. spectra with extinctions comparable to those of octaethylporphyrin.
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.
