Condensation Friedel-Crafts reactions

The molten material, after holding for 4 h at 78°C in a stainless steel vessel, underwent a thermal runaway reaction and 500 kg erupted through the vent line. It was later found that addition of 0.1% of rust to the hot material led to an accelerating self-condensation Friedel-Craft reaction, catalysed by iron(III) chloride, which led to formation of poly-benzyls accompanied by evolution of hydrogen chloride. 

Benzilic acid rearrangement Benzoin reaction (condensation) Blanc chloromethylation reaction Bouveault-Blanc reduction Bucherer hydantoin synthesis Bucherer reaction Cannizzaro reaction Claisen aldoi condensation Claisen condensation Claisen-Schmidt reaction. Clemmensen reduction Darzens glycidic ester condensation Diazoamino-aminoazo rearrangement Dieckmann reaction Diels-Alder reaction Doebner reaction Erlenmeyer azlactone synthesis Fischer indole synthesis Fischer-Speior esterification Friedel-Crafts reaction... 

Friedel-Grafts Reaction. Until quite recently, the manufacture of anthraquiaone ia the United States was by the Friedel-Crafts reaction benzene [71-43-2] and phthaUc anhydride [85-44-9] condense ia the preseace of anhydrous aluminum chloride to give o-benzoylbenzoic acid [85-52-9] which, on treatment with concentrated sulfuric acid, is converted iato anthraquiaoae ia high yields and purity (33). 

An ingenious synthesis of 1-arylisoindolcs has been developed by Vebor and Lwowski, based upon the reaction of an o-phthalimido-methylbenzophenone (41, R = aryl) with hydrazine (Table IV). The benzophenone is prepared by a Friedel-Crafts reaction with o-phthalimidomethylbenzoyl chloride (40). The mechanism of isoindole formation can be represented sehematically by a sequence involving attack by hydrazine at the imide to give the ring-opened hj drazide (42), followed by cyclization to phthalazine-l,4-dione (44) with displacement of the o-aminomethylbenzophenone (43). Intramolecular condensation of the latter can lead, via the isoindolenine... 

There is some similarity between the cracking of petroleum and the cracking of biomass. However, biomass is more complex chemically both in terms of structrual types and functional groups. In petrochemistry, hydrocarbons are fractionated and they are then functionalized by oxidation, halogenation, nitration and other chemical processes so as to add value. The commodity chemicals are then built up into more complex molecules using such popular synthetic methods as Friedel Craft reactions, Michael and aldol condensations, and Heck and Suzuki couplings. The speciality products of these reactions are then further elaborated into formulations for use in everyday applications ranging from personal care... 

The acid, referred to as tetra acid , is prepared as follows In a Friedel-Crafts reaction, acenaphthene 72 is reacted with malonic dinitrile and aluminum chloride. The resulting condensation product 75 is oxidized with sodium chlorate/hy-drochloric acid to form the dichloroacenaphthindandione 76. Oxidation with sodium hypochlorite solution/sodium permanganate affords naphthalene tetracar-boxylic acid 68, mostly existing as the monoanhydride 68a. The dianhydride, on the other hand, evolves only after drying at approx. 150°C. 

This procedure is based upon a study 1 of the method outlined in the patent literature.2 The procedure is a general one and may be used for the condensation of succinic anhydride with naphthalene and with the mono- and dimethylnaphthalenes, although in no other case are the purification and separation of isomers so easily accomplished. In this particular type of condensation, as well as in certain other types of Friedel-Crafts reactions, nitrobenzene is far superior to the solvents which are more frequently employed. This is partly because of its great solvent power and partly because it forms a molecular compound with aluminum chloride, and so decreases the activity of the catalyst in promoting side reactions. 

Saturated non-acetal dimers, such as 153 and 154, can be prepared from 151 via aluminium acetylide condensations or Friedel-Crafts reactions. Although the acetylenic dimer 153 is /3-linked to C-10 of the artemisinin skeleton, the aryl dimer 154 is a-linked <1999JME4275>. 

As shown in Eq. (14), poly(arylene ether imide)s were synthesized by the Friedel-Crafts reaction of diphenoxydiimide monomers and iso or terephthaloyl chloride [51], The diphenoxydiimide monomers were readily prepared by the condensation of 4-phenoxyaniline with appropriate aromatic tetracarboxylic dianhydrides. Several poly(arylene ether imide)s of controlled molecular weight (Mn = 40,000 g/mol) prepared by this route are presented in Table 21. As... 

Synthesis (Tull et al. (Merck Co.), 1975 1976) Friedel-Crafts reaction of fluorobenzene and a-bromoisobutyryl bromide gives 5-fluoro-2-methylindan-1-one, which is treated with 4-methylthiobenzylmagnesium chloride to yield 5-fluoro-2-methyl-1-(4-methylthiobenzyl)indene. Condensation with glyoxylic acid in the presence of N-benzyltrimethyl ammonium hydroxide (Triton B) gives 3-carboxy methylene-5-fluoro-2-methyl-1 -(4-methylthio-ben-zyl) indene, which is isomerized in acid to 5-fluoro-2-methyl-1-(4-methylthiobenzylidene)indene-3-acetic acid. Oxidation with hydrogen peroxide affords sulindac. 

Applied to the synthesis of hydrocarbons the following results have been obtained by this new method. 9 10-Diphenyl-9 10-dihydroanthracene is formed by the condensation of benzene and chloroform, whilst in the ordinary Friedel-Crafts reaction (A., 194, 254 227, 107) triphenyl-methane (Preparation 6) is the main product, traces of chlorarylmethanes and tetraphenylethane (B., 26, 1952) being also formed. The same compound is also obtained from benzal chloride and benzene. Carbon tetrachloride and benzene give 9 9 10 10-tetraphenyl-9 10-dihydroanthracene as do also phenylchloroform and benzene. In the older reaction triphenylchloromethane (p. 432) is the chief product. 

The dyes are synthesized either from A-alkylnaphtholactams, obtained by intramolecular Friedel-Crafts reaction of the 1-alkylnaphthylamine carboxylic acid chlorides, or by subsequent alkylation of the dye bases obtained by condensation of naphtholactam with aromatic amines [47],... 

In the cyclization of 7-3-pyrenylbutyric acid (Table IV) the higher yields obtained by the Friedel-Crafts reaction (examples 7 and 8) again involved the use of mild conditions. Even with the mild condensing agent, stannic chloride, it was foilnd unnecessary to heat the reaction mixture in order to obtain 96% yields (example 8). 

There are only a few products manufactured in any considerable tonnage by condensation and addition (Friedel-Crafts) reactions, but those that are find use in several different intermediates and particularly in making high-quality vat dyes. 

Bis(r 6-aryl) derivatives of molybdenum have been prepared by the co-condensation of the arene and molybdenum atoms at 77 K.305 Friedel-Crafts reactions catalysed by [(r 6-arene)Mo(CO)3] complexes have been developed further, and such reactions with organic halides shown to proceed via an ionic mechanism.306... 

As industrial relevant Friedel-Crafts reaction, the synthesis of Bisphenol-F, a material for epoxy resin, from phenol and formaldehyde was chosen [57]. This reaction involves formation of higher order condensates such as tris-phenols. To minimize the latter, the molar ratio of phenol to formaldehyde is set to a very high value (30-40), which is more than 15 times larger than the amount theoretically necessary. Three types of micromixers were used. These are a T-shaped mixer with 500 pm inner diameter, a multilaminating interdigital micromixer with 40 pm channels and a so-called self-made K-M micromixer with center collision mixing. 

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