Eine Synthese des Pyrens

Abstract

Dieser neue Weg, der auch eine Reihe anderer /ihnlich gebauter Farbstoffe zug/inglich macht, hat den Besitz einer hinreichenden Menge yon Pyren zur Bedingung. Da nun dieses aus den am hachsten siedenden Anteilen des Stein

Mononucleating Bis(β-diketonate) Ligands and Their Titanium(IV) Complexes

“…Preparation of the 2,2‘-bis(2,4-dioxobutyl)biphenyl derivatives R 2 BobH 2 (Scheme ) proceeds from commercially available 2,2‘-bis(bromomethyl)biphenyl via known biphenyldiacetonitrile 17 and -diacetic acid, which is then converted to the acyl chloride with phosphorus pentachloride. In this case, treatment of the diacyl chloride with 2 equiv of enolate and 2 equiv of lithium hexamethyldisilazide fails, presumably because the excess base reacts with the α-protons of the acid chloride.…”

“…2,2 ‘ -Biphenyldiacetic Acid, (2-HOOCCH 2 C 6 H 4 ) 2 . (2-HOOCCH 2 C 6 H 4 ) 2 was prepared using the procedure of Weitzenböck and was isolated in 84% yield. 1 H NMR (C 6 D 6 ): δ 3.18 (d, 18 Hz, 2H, C H H‘), 3.61 (d, 18 Hz, 2H, CH H ‘), 6.96 (dd, 8, 1 Hz, 2H, 6-H), 7.01 (td, 7, 2 Hz, 2H, 4- or 5-H), 7.05 (dd, 8, 2 Hz, 2H, 3-H), 7.11 (td, 8, 2 Hz, 2H, 4- or 5-H).…”

Pyrene-Based Materials for Organic Electronics

“…The search for an effective method to prepare pyrene lead Weitzenböck in 1913 to the first synthesis of pyrene, starting from o , o ′-ditolyl . Until the 1950s, several other preparative routes toward pyrene were presented. − Modernization of the distillation process of coal tar, as well as the destructive hydrogenation of hard coal, yielded considerable quantities of pyrene and other polycyclic hydrocarbons, making pyrene of commercial use.…”

“…The search for an effective method to prepare pyrene lead Weitzenb€ ock in 1913 to the first synthesis of pyrene, starting from o,o 0 -ditolyl. 6 Until the 1950s, several other preparative routes toward pyrene were presented. 7À16 Modernization of the distillation process of coal tar, as well as the destructive hydrogenation of hard coal, yielded considerable quantities of pyrene and other polycyclic hydrocarbons, making pyrene of commercial use.…”

Synthetic studies on phosphorylating reagent. II. 2-(N,N-Dialkylamino)-4-nitrophenyl phosphate and its use in the synthesis of phosphate esters

“…Bimolecular attack upon phosphate ester dianions makes little contribution to the overall reaction in the presence or absence of micelles, except at very high pH,7®•11"13 and in the absence of micelles amines can attack p-nitrophenyl phosphate upon the aryl group, as well as speed formation of p-nitrophenoxide ion. 14 There are similarities between the spontaneous hydrolyses of dinitrophenyl phosphate dianions and 2,4-dinitrophenyl sulfate monoanion, in that both involve phenoxide ion elimination,15 and are catalyzed by cationic micelles,16 which also markedly change the relative importance of spontaneous hydrolysis of 2,4-dinitrophenyl sulfate monoanion and bimolecular attack by amines upon the aryl group.…”