182918-50-9Relevant academic research and scientific papers
Synthesis and Reactions of 4-Acyl/Carbamoyl-N-aryl-3-chloro-pyrrol-2,5-diones: Crystal Structure of a Supramolecular Ribbon Based on Hydrogen Bonds [1]
Saalfrank, Rolf W.,Hoerner, Bernd,Reck, Stephan,Nachtrab, Jochen,Peters, Eva-Maria,Peters, Karl,Von Schnering, Hans Georg
, p. 1084 - 1098 (2007/10/03)
Reaction of malondiamides 1 with oxalyl chloride (2) leads to the formation of 2,3-dioxo-2,3-dihydrofuran hydrochlorides 3 and 2,3-dioxo-2,3-dihydro-furanes 4, respectively. The structure of 3a was established by X-ray diffraction. The β-oxo-dibenzylamides 5 react with 2 regiospecifically to give the 2,3-dioxo-2,3-dihydrofuranes 6. Addition of water in 1,4-position to 6a yields hydroxy-enol 7, which forms bimolecular aggregates via intermolecular hydrogen bonds as shown by X-ray analysis. Intramolecular C,N-bisacylation of β-oxoamides 8 and malondiamides 11 with 2 leads to the pyrrol-2,5-diones 9 and 12. Reaction of the enols 9 and 12 with thionyl chloride leads to 3-chloro-pyrrol-2,5-diones 13. 3-Amino-pyrrol-2,5-diones 15 are obtained from 13 and amines 14, while 1,ω-diamines 16 yield the bispyrrol systems 17. X-ray diffraction analysis of 17g reveals a supramolecular ribbon based on intermolecular hydrogen bonds between two different conformeres of 17g and in addition establishes unequivocally the imid-structures of 9 and 12. Intermolecular cyclisation of 13 with amino-tetrazol 18 gives the azido-pyrrolo-pyrimidine-diones 20, which reacts with triphenylphosphane to give phosphinimines 22. The structure of 22a was established by X-ray diffraction.
