Diphenic acid, preparation

Diphenic acid. Phenanthrene upon oxidation in acetic acid solution at 85° with 30 per cent, hydrogen peroxide gives diphenic acid (diphenyl-2 2 -di-carboxyHc acid) no phenanthraquinone is formed under these experimental conditions. The reaction is essentially an oxidation of phenanthrene with peracetic acid. (For another method of preparation, see Section I V,74.)... 

An interesting coupling reaction with the diazonium salt derived from anthranilic acid leads to an excellent method for the preparation of diphenic acid. The reaction occurs with cuprous salts in ammoniacal solution y /COOH 2JJC1 y yCOOIl 2Cu+... 

The heterocyclic acylphosphines (52) and (53) have been prepared by the reaction of phenylbis(trimethylsilyl)phosphine with the acid chlorides derived from phthalic and diphenic acids. The reaction of 2,3-dichloromaleic anhydride or thioanhydride with phenylbis(trimethylsilyl)phosphine gives derivatives of the 1,4-dihydro-p-diphosphorin system (54).45... 

Diphenic acid has been prepared by the reduction of diazotized anthranilic acid with cuprous ion,5 Ullman coupling of potassium... 

Diphenic acid was first prepared by oxidizing phenanthrene-quinone with chromic acid.1 Many later workers2 have modified this process in minor details. Vorlander and Meyer 3 were the first to prepare diphenic acid from diazotized anthranilic add and cuprous oxide, but their process is not well adapted to large scale preparation. Inasmuch as pure phenanthrene is now very difficult to obtain in quantity, the present process was devised for relatively large scale operation. 

Diphenic acid has been prepared by the reduction of diazotized anthranilic acid with cuprous ion,6 Ullman coupling of potassium o-bromobenzoate,6 and oxidation of phenanthrene or phen-anthrenequinone with various oxidizing agents.7 The latter methods have been reviewed recently.7 The ozonolysis method has also been carried out in solvents 8 that do not react with the zwitterion intermediate. ... 

Diorganotin(iv) derivatives of diphenic acid 233 were prepared by reaction of dialkyltin(iv) oxide with diphenic acid and its sodium salt in 1 1 molar ratio (Figure 9). Structure of these compounds was confirmed by IR, H, and 13C... 

Several dibasic acid halides are best prepared by this method from the readily available anhydrides. Thionyl chloride in the presence of a small amount of zinc chloride converts succinic and phthalic anhydrides to succinyl chloride (74%) and phthalyl chloride (86%), respectively. Phosphorus halides are used in similar preparations of phthalyl bromide (83%) and diphenic acid chloride (71%). ... 

Diphenic acid itself can be prepared without isolation of phenanthrenequinone by direct oxidation of phenanthrene with hydrogen peroxide in refluxing acetic acid. ... 

The reaction apparently involves free-radical mechanism, but arylcopper compounds take a part, at least under certain reaction conditions, as clearly demonstrated through Cohen s concise results [99,100]. The reaction was discovered as a side-reaction during probes of the Gatterman synthesis of aryl halides from diazonium salts and copper(l) halides. Probably the most known example is very practical preparation of diphenic acid (57) starting from anthranilic acid (58). The reaction is usually conducted by adding an aqueous diazotized anthranilic acid solution (diazonium salt 59) to the copper(l) reagent, in situ obtained by reduction of CUSO4 with an equimolar amount of hydroxylaminc in aqueous sodium hydroxide solution, to produce diphenic acid with a 80-90% yield [99,100], Scheme 25. 

New benchrotrene derivatives have been prepared by reactions of [Cr(CO)s], etc., with oestrone and related steroids, phenalene, 2,6,15,19-tetrathia-[7.7]paracyclophane, PhjAs, and diphenic acid and related compounds. Ring-substituted derivatives of [( benzaldehyde)Cr(CO)3] have been resolved into enantiomeric forms. Reactions of carbene complexes of the type [(OQs-CrC(OMe)Ar] with alkynes have afforded derivatives of [(jy -naphthalene)-Cr(CO>3] (see Vol. 8, refs. 393, 394). 

The second promising new type of polymer was made from 2,2 -diphenylethynyl-4,4 -diphenic acid units which cure on heating to give phenylbenzanthracene units in the polymer chain. The new polymer also belongs to the polyaromatic ether-keto-sulfone series. This polymer was prepared from dimethyl 4,4 -diphenate by direct iodination in sulfuric acid with a silver sulfate catalyst to give the 2,2 -diiodo derivative in 80-85% yield. When hydrolized to the acid it could be converted to the acid chloride on treatihent with oxalyl chloride in pyridine solution. 

OXIDATION OF KETONES AND QUINONES 9-4. Preparation of Diphenic Acid 4 ... 

The aldehyde 38 was obtained from 35, by way of 36 and 37, by the carbodiimide—dimethyl sulfoxide oxidation procedure52 in the presence of 3-(3-dimethylaminopropyl)-l-ethylcarbodiimide hydrochloride (EDAC)53 and dichloroacetic acid. It was isolated in the form of its crystalline 1,3-diphenylimidazolidine derivative (39) by trapping the freshly prepared aldehyde 38 with N,N -diphen-ylethylenediamine. (This reagent was developed by Wanzlick and Lochel54 for the selective derivatization of aldehydes, and has been exploited for the isolation of nucleoside 5 -aldehydes55 and other aldehydo derivatives of carbohydrates by Moffatt and coworkers.52(b))... 

Salt crystals were prepared between cyclopropane mesoacid 76 and ten different optically pure amines. Solid-state irradiation of these crystals caused photoisomerization affording the optically active frans-cyclopropane 77 in moderate enantiomeric excesses (Scheme 17) [84]. The best results were obtained using (S)-proline, which gave 79% ee at low conversion. When salt crystals of the diphen-ylbenzoyl acid 78 with several optically pure amines were irradiated, then the compounds 79 or 80 of near quantitative enantiomeric excesses were obtained, with a slight diminution in ee as the conversion was increased [85]. 

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