The synthesis and properties of 1,4‐diketo‐pyrrolo[3,4‐C]pyrroles

Abstract

Syntheses and mechanistic aspects of formation of 1,4-Diketopyrrolo[3,4-c]pyrroles (DPP) are discussed. The chemical reactivity of this novel class of heterocycles is illustrated by specific electrophilic aromatic and N-substitution reactions, as well as by nucleophilic transformations of the bicyclic lactam carbonyl group. X-ray structural analysis of the diphenyl-DPP molecule reveals significant intermolecular hydrogen bonding and IT-x interactions in the solid state.

Geometry and Raman spectra of P.R. 255 and its furo-furanone analogue

“…The phenyls on both BFFB [8,9] and BPPB [6,10] are slightly twisted with respect to a central heterocycle plane, i.e. the molecules are of C i symmetry by X-ray diffraction, not C 2h as quasiplanar (phenyls are not rotated, but the molecular plane shows a little sigmoid deflection [11]) 1,4-diphenyl-buta-1,3-diene (DPB), that can be considered as their hydrocarbon backbone.…”

“…Pigment Red 255 in a suitable supramolecular form) and at least five its on-aryl substituted symmetrical derivatives form a commercially very successful family of high performance organic pigments covering a color range from orange to purple [3,4]. Their unique solid state properties relate to the intermolecular hydrogen bonding of the molecules through CO and NH groups in a crystal layer and strong p-p interlayer stacking [5][6][7].…”

Synthesis and Thermal Stability of Solvent Soluble Dyes Based on Dimerized Diketo-pyrrolo-pyrrole Pigment

“…Pigment Red 254, which is based on DPP (Diketopyrrolo-pyrrole) and was first synthesized by Ciba-Geigy, has mainly found use in paints and inks as well as LCD color filters owing to its excellent thermal stability and bright red shade. [6][7][8][9] DPP derivatives are known for their poor solubility in most organic solvent due to their tendency to form strong - interactions and intermolecular hydrogen bonds. Much effort has focused on functionalizing them to improve their solubility.…”

Preparation of Solvent Soluble Dyes Derived from Diketo-pyrrolo-pyrrole Pigment by Introducing an N-Alkyl group

“…[12][13][14] Single crystal X-ray structural studies [14][15][16] on DPP clearly reveal the existence of chains of hydrogen bonds between the N-H of one molecule and the oxygen of another molecule which mainly contributes to excellent thermal stability and lack of solubility in most solvents. Therefore, the cancellation of the intermolecular hydrogen bonding via N-methylation [16][17][18] or N-arylation 19,20 of DPP yields not only more soluble derivatives, in the order DPP ≪ N-monomethyl-DPP ≪ N,N'-dimethyl-DPP, but also less thermal stable analogues.…”