Diphenyl-2-carboxylic acid

Nitration of diphenyl-2-carboxylic acid with concentrated nitric acid at room temperature gives a 79 2T mixture of 2 -nitrodiphenyl-2-carboxylic acid (2) and 4 -nitrodiphenyl-2-carboxylic acid (3). However, nitration with dinitrogen pentoxide in carbon tetrachloride at 0°(30 niin.) gave (2) in good yieid as the sole product. ... 

Corbellini and Angeletti (24) and Jamison and Turner (54) investigated the activation of 2 -(a-hydroxyisopropyl)diphenyl-2-carboxylic acid (IX) by means of brucine, and noted the crystallization of the pure brucine ( —) salt, from alcohol, in yields as high as 97.6%,... 

More complex cases are very frequent. The choice between 1 -2 -thenoylphenan-threne, 2-l -phenanthroylthiophen, and 1-phenanthryl 2-thienyl ketone for III, or between p-phenylbenzoic acid and diphenyl-carboxylic acid for IV illustrates the principle. The 1945 Chemical Abstracts index lists four methods of naming monoketones. Each... 

The anti-inflammatory agent Oxapro2in, 2-(4,5-diphenyl-2-oxa2ole)propionic acid mono aluminum and dihydroxyalurninum salts, is made by reaction of the sodium salt with aluminum sulfate under controlled conditions (96). Again, the aluminum salts of many carboxylic acid based dmgs are less irritating, ulcerous, and/or toxic, and have a more pleasant taste than their parent acids. 

Hi) Electrochemical reactions and reactions with free electrons Electrochemical oxidation of 3-methyl-l-phenylpyrazole gave the 3-carboxylic acid whereas electrochemical reduction (Section 4.04.2.1.6(i)) of l,5-diphenyl-3-styrylpyrazole produced the A -pyrazoline (B-76MI40402) with concomitant reduction of the exocyclic double bond (343). 

The treatment of 4-benzoyl-3-phenylisoxazolin-5-one with KOH generated 3,5-diphenyl-isoxazole-3-carboxylic acid via a ring-opened intermediate as shown in Scheme 69 (61CB1956). 

Azepine-1-carboxylic acid, methyl ester, tricarbonyliron complex X-ray, 7, 494 <70JCS(B)1783) 4//-Azepine-2-carboxylic acid, 6,7-diphenyl-, methyl ester... 

C NMR, 7, 498 (79TH51600) 2H-Azepine-4-carboxylic acid, 7-(4-bromophenyl)-3-methoxy-2-oxo-6-phenyl-X-ray, 7, 494 <79H(12)1423> 3H-A2epine-4-carboxylic acid, 6-acetyl-2-ethoxy-3-oxo-7-phenyl-, ethyl ester H NMR, 7, 503 <81H(16)363) 3H-Azepine-4-carboxylic acid, 2,6-diethoxy-3-oxo-7-phenyl-, ethyl ester H NMR, 7, 503 <81H(16)363) 3H-Azepine-4-carboxylic acid, 2-ethoxy-3-oxo-6,7-diphenyl-, ethyl ester HNMR, 7, 503 <81H(16)363) 3H-Azepine-4-carboxylic acid, 2-ethoxy-3-oxo-7-phenyl-, ethyl ester... 

Oxa-1 -azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid, 8-oxo-7-(phenylacetamido)-3-(5-tetrazolylthiomethyl)-, diphenyl methyl ester X-ray, 7, 349 (B-82MI51206)... 

A -0-2-Isocephem-4-carboxylic acid, 1-P-phenoxyacetamido-3-methyl-1 -oxo-synthesis, 1, 430 Isochroman, 1,3-diphenyl-synthesis, 3, 787, 788 Isochroman, 3,4-diphenyI-conformation, 3, 631 Isochroman, 2-methyl-synthesis, 3, 788 Isochroman, 3-phenyl-synthesis, 3, 788 Isochroman, (-)-)-(i )-3-phenyI-stereoselective synthesis, 3, 789 Isochroman-4-carboxylic acid, l-oxo-3-phenyl-synthesis, 3, 860 Isochroman-I,3-diones, 4-acyI-synthesis, 3, 831 Isochromanols dehydration, 3, 767 isochroman synthesis from, 3, 789 Isochroman-1-one, 3-aryl-synthesis, 3, 858, 860... 

Oxetane, 3,3,4,4-tetramethyl-2,2-diphenyl-pyrolysis, 7, 372-373 Oxetane, vinyl-thermal stability, 7, 370 Oxetane-3-carboxylic acid, 3-hydroxy-2,2,4,4-tetramethyl-synthesis, 7, 394... 

H-Pyran-3-carboxylic acid, 6-amino-5-cyano-2,4-diphenyl-ethyl ester... 

The smooth intramolecular nucleophilic displacement of biphenyl carboxylic acids leading to benzocoumarins (See Section II.A.) inspired also investigation of the behavior of similar diphenyl ether, diphenyl sulfide and A-methyldiphenyl amine derivatives 458 under similar conditions. However, all these attempts to achieve cyclization to tricyclic compounds 459 were unsuccessful, probably due to the unfavorable stereochemistry for the formation of the required seven-mem-bered transition states and also to the presence of the deactivating bridge groups X (Eq. 42) [68JCS(C)1030]. 

Diketones 1 can be converted into the salt of an a-hydroxy carboxylic acid upon treatment with alkali hydroxide after acidic workup the free a-hydroxy carboxylic acid 2 is obtained. A well-known example is the rearrangement of benzil (R, R = phenyl) into benzilic acid (2-hydroxy-2,2-diphenyl acetic acid). The substituents should not bear hydrogens a to the carbonyl group, in order to avoid competitive reactions, e.g. the aldol reaction. 

Carboxylic acids, a-bromination of 55, 31 CARBOXYLIC ACID CHLORIDES, ketones from, 55, 122 CARBYLAMINE REACTION, 55, 96 Ceric ammonium nitrate [Ammonium hexa mtrocerate(IV)[, 55, 43 Chlorine, 55, 33, 35, 63 CHROMIUM TRIOXIDE-PYRIDINE COMPLEX, preparation in situ, 55, 84 Cinnamomtnle, a-phenyl- [2-Propeneni-tnle 2,3-diphenyl-], 55, 92 Copper(l) iodide, 55, 105, 123, 124 Copper thiophenoxide [Benzenethiol, copper(I) salt], 55, 123 CYCLIZATION, free radical, 55, 57 CYCLOBUTADIENE, 55, 43 Cyclobutadieneiron tricarbonyl [Iron, tn-carbonyl(r)4-l,3-cyclo-butadiene)-], 55,43... 

CjpHujNO, 128289-78-1) see Moexipril [6R-[6a,7p(lf )]]-7-[[5-(benzoylamino)-6-(diphenyl-methoxy)-l,6-dioxohexyl]amino]-3-(chloromethyl)-8-oxo-5-thia-l-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid diphenylmethyl ester (C47H42CIN3O7S) see Cefixime [6fi-[6a,7P(R )]]-7-[[5-(benzoyIamino)-6-(diphenyl-methoxy)-l,6-dioxohexyl]amino]-3 -ethenyl-8-oxo-5-thia-... 

Carboxylic acids can also be activated by the formation of mixed anhydrides with various phosphoric acid derivatives. Diphenyl phosphoryl azide, for example, is an effective reagent for conversion of amines to amides.140 The proposed mechanism involves formation of the acyl azide as a reactive intermediate. 

The kinetics of deuterium isotope exchange between diphenyl phosphine and t-butylthiol have been studied by H n.m.r. spectroscopy.274 A negative temperature coefficient was observed for the reaction of a perf1uoroalky1 phosphite with a fluorinated aldehyde.275 The kinetics for the reaction of alcohols with phosphoryl trichloride bore strong similarities to those of carboxylic acid derivatives.276 An interesting report desribed the solvolysis of ary 1 hydroxymethyl-phosphonates. It was shown that a phosphoryl group does not prevent carbocation formation on an immediately adjacent carbon atom.277... 

To a solution of oxalic chloride (5 g) in dichloromethane, a solution of diphenyl amine (5 g) in dichloromethane was added dropwise and refluxed for 30 min. The solution was concentrated (50%) and aluminum trichloride (8 g) added in portions. The mixture was refluxed for 45 min and the solvent evaporated. To this residue hydrochloric acid in ice water (1 M) was added and the red-colored precipitate filtered. The precipitate was dissolved in potassium hydroxide (10% in water), refluxed overnight, and poured into hydrochloric acid in ice water (5 M). The yellow acridine-9-carboxylic acid was filtered, washed with water, and dried. 

The specific feature of the bonds also affects its chemical behaviour and the stereochemistry of substitution reactions. For example in the conversion of (-) trans -2, 3 diphenyl cyclopropane carboxylic acid into (+) 1, 3 diphenylallene the optical activity is retained. 

Calculation of EM. The reference intramolecular reaction is nucleophilic attack by the anion of a carboxylic acid of pK, 3.15 on 2-phenoxy-l,3,2-dioxaphosphorinan-2-oxide. The rate constant for this reaction can be calculated as 7.67 x 10-10 dm3 mol 1 s-1 at 39° using the formula derived by Khan and Kirby (1970), and allows the direct calculation of the EM for the corresponding intramolecular reaction (COO-—P3—6n of A.5.5). The EM is assumed to be the same for the corresponding endocyclic reaction of the diphenyl ester anion (A.5.6), and has been shown not to differ significantly for endocyclic and exocyclic displacements (Bromilow etal., 1972)... 

The reaction of 3-aminopyrazine-2-carboxylic acid and EMME at 160-I80°C for 2 hr, or in diphenyl ether at 200°C for 2 hr, afforded 2-pyrazinylaminomethylenemalonate in 60% yield (70T3069 71IJC201) (Scheme 13). 

Raychaudhuri and Basu investigated the formation of side products in the large-scale cyclization of diethyl /V-(3-chlorophenyl)aminomethy-lenemalonate (250) in diphenyl ether (70J1C25). As side products, 7-chloro-1-ethyl-l,4-dihydro-4-oxoquinoline-3-carboxylic acid (551), 7-chloro-4-ethoxyquinoline (552), and 7-chloro-l-ethyl-4(l//)-quinoline (553) could be isolated. These were probably formed from the primarily cyclized product, ethyl 7-chloro-4-hydroxyquinoline-3-carboxylate. The quantities of the side products depended on the reaction temperature during the cyclization, the duration of heating, and the purity of the starting N-(3-chlorophenyl)aminomethylenemalonate (250). 

A second example of the use of ionic chiral auxiliaries for asymmetric synthesis is found in the work of Chong et al. on the cis.trans photoisomerization of certain cyclopropane derivatives [33]. Based on the report by Zimmerman and Flechtner [34] that achiral tmns,trans-2,3-diphenyl-l-benzoylcyclopropane (35a, Scheme 7) undergoes very efficient (0=0.94) photoisomerization in solution to afford the racemic cis,trans isomer 36a, the correspondingp-carboxylic acid 35b was synthesized and treated with a variety of optically pure amines to give salts of general structure 35c (CA=chiral auxiliary). Irradiation of crystals of these salts followed by diazomethane workup yielded methyl ester 36d, which was analyzed by chiral HPLC for enantiomeric excess. The results are summarized in Table 3. 

Scheme 7 Photoisomerization of salts of frans,frans-2,3-diphenyl-1-benzoyl-cyclopropane-p-carboxylic acid...

Ring opening of 97 as indicated gives the 9-(a-amino-Q -phenylmethyl) purine 98, which by a base-catalyzed elimination of benzylideneimine is converted into 6,8-diphenyl-2-methylthiopurine 99. This pteridine-purine transformation has a close resemblance to the enzyme-catalyzed ring contraction of tetrahydropteridine into xanthine-8-carboxylic acid (64MI1), in which reaction it was proved by radioactive labeling that it is exclusively C-7 that is expelled. 

Reacting 3-chloro-4-fluoroaniline and ethyl ethoxymethylenmalonate gives the snbsti-tntion prodnct (33.2.15), which upon heating in diphenyl ester cyclizes into ethyl ester of 6-flnoro-7-chloro-l,4-dihydro-3-quinolin-4-on-carboxylic acid (33.2.16). Direct treatment of the prodnct with ethyl iodide in the presence of triethylamine and snbseqnent hydrolysis with a base gives l-ethyl-6-flnoro-7-chloro-l,4-dihydro-3-qninolin-4-on-carboxylic acid (33.2.17). Reacting this with piperazine gives norfloxacin (33.2.18) [70-75]. 

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