Notes- The Crystal and Molecular Structures of Overcrowded Compounds. V. The Double Cyclization of Diphenethylacetic Acids

Abstract

NOTES 557 ton and Overhoff state: "Very numerous attempts were made to condense phthalimidohalogenoacetones with ethyl sodiochloromalonate and indeed with ethyl sodiomalonate itself under various conditions, but all were in vain. The halogenoacetones reacted exothermically with the sodiomalonates with rapid elimination of the sodium halide, but normal condensation did not occur, the products consisting for the most part of highly pigmented resins."The coupling of III with sodium diethylmalonate was studied in several solvents under various conditions and was found to yield several products. At refluxing temperature in alcohol sodium bromide was formed, but attempts to crystallize a product from alcohol, ether, and chloroform failed. A very small amount of material was crystallized from acetone, but was not studied further. When III was added as a solid to an alcoholic solution of sodium diethylmalonate at room temperature the reaction mixture crystallized spontaneously.The material (obtained in high yield, but not the desired product) was recrystallized from 95% ethanol in which it is only slightly soluble, m.p. 278-279°. A sample was prepared for analysis by recrystallization from W,W-dimethylformamide by addition of water and also from alcohol-water.The analysis suggested phthalimide (calculated

Characterization of polyelectrolyte effect in poly(acrylic acid) solutions

“…2‐Phenethyl‐4‐phenylbutanoic acid ( 1 p ) was converted into the 2‐phenethyltetralone 8 in 84 % yield [Eq. (2)] 37. The fluorine substituents are again necessary to promote the second Friedel–Crafts‐type ring closure ,…”

“…The 1,1‐difluoroalk‐1‐enes 1 i – n were prepared by a method similar to that used for 1 h . The dichloroalkene 1 o 46 and the carboxylic acid 1 p 37 were prepared by the literature procedures. The spectral data for 1 a were in agreement with those reported in the literature 17a.…”

Domino Friedel–Crafts‐Type Cyclizations of Difluoroalkenes Promoted by the α‐Cation‐Stabilizing Effect of Fluorine: An Efficient Method for Synthesizing Angular PAHs

“…[16a] The 1,1-difluoroalk-1-enes 1 i-n were prepared by a method similar to that used for 1 h. The dichloroalkene 1 o [46] and the carboxylic acid 1 p [37] were prepared by the literature procedures. The spec-Domino cyclizations of 1,1-difluoroalk-1-enes: The synthesis of 7 c is described as a typical procedure.…”

“…(2)]. [37] The fluorine substituents are again necessary to promote the second Friedel-Crafts-type ring closure.…”

Concise Synthesis of Halogenated Chrysenes ([4]Phenacenes) that Favor π-Stack Packing in Single Crystals

“…Acenes, PAHs with fused benzene rings in a rectilinear arrangement, have long been notable molecules of particular interest, especially those with more than four rings, and the derivatives of acenes with improved properties such as thermal stability or packing structures have contributed significantly to the development of the field of organic devices . Phenacenes, PAHs with fused benzene rings in a zigzag arrangement, have recently emerged as new candidate molecules with ideal properties, such as stability in FETs or blue light emission in LEDs. , However, synthetic access to the phenacene derivatives is scarce, , which hampers further exploration of the potential applications of the phenacenes. Here we report on a concise two-step method for the synthesis of chrysene ([4]phenacene) derivatives.…”