Substituent effects on the acidity of weak acids. 1. Bicyclo[2.2.2]octane-1-carboxylic acids and bicyclo[1.1.1]pentane-1-carboxylic acids

The acidities of 3- and 4-substituted bicyclooctane-1-carboxylic acids and 3-substituted bicyclo[1.1.1]pentane-1-carboxylic acids have been calculated at the MP2/6-311++G** theoretical level. There is good agreement between the calculated and observed gas-phase acidities. The acidities of the 4-substituted bicyclooctane acids were found to be linearly dependent on the C-X bond dipoles, as expected from a field effect. The substituents had a negligible effect on the electron density at C1. The difference in acidity between 4-chlorobicyclo[2.2.2]octane-1-carboxylic acid and the parent acid (6.2 kcal/mol) is reproduced by the Kirkwood-Westheimer treatment of substituent effects on acidity, but only if the bicyclooctane ring is given an effective dielectric constant of unity. The acidities of the 3-substituted bicyclooctane acids are linearly related to the corresponding 4-substituted acids with a slope of 0.9. The acidities of the 3-substituted bicyclo[1.1.1]pentane-1-carboxylic acids are linearly related to the C-X bond dipoles for this ring system (which are different than those for the bicyclooctanes), and they are also linearly related to the acidity of the 4-substituted bicyclo[2.2.2]octanecarboxylic acids with a slope of 1.34. The larger slope is due to the smaller bridgehead-bridgehead distance in the bicyclopentane ring than in bicyclo[2.2.2]octane.     

1,2-Diacyl-1-arylhydrazines. 1. Derivatives of 2-hydroxy- and 2-halogenobenzoic acids

New 1,2-diacyl-1-arylhydrazines, containing a hydroxy group or a mobile halogen atom in the 1-acyl fragment, were obtained by the reaction of the arylhydrazones of acetyl and benzoyl chlorides with the salts of 2-hydroxy-, 2-acetoxy-, and 2-halogeno-3-nitrobenzoic acids. 1-(2-Hydroxybenzoyl)-1-aryl-2-acylhydrazines could not be converted into cyclic products. On heating in alkaline and acidic media elimination of the more hindered salicyloyl group and not dehydration occurred. When boiled in DMF in the presence of bases, 1-(2-halogeno-3-nitro-5-R-benzoyl)-1-aryl-2-acylhydrazines gave 2-aryl-5-R-7-nitroindazol-3-ones and not the expected 4,5-dihydrobenzo[f]-1,3,4-oxadiazepin-5-ones.A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan' Scientific Center, Russian Academy of Sciences, 420083 Kazan'. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 6, pp. 1424–1430, June, 1992.     

Phosphorus-containing aminocarboxylic acids. 1. Method of preparation of phosphonate-type compounds

A method is described for the synthesis of phosphorus-containing amino carboxylic acids, by the Michaelis-Bekker or Arbuzov phosphorylation of -haoalkylacetamidomalonic esters. The latter were obtained by alkylating the sodium salt of acetamidomalonic ester with an excess of the ,-dihaloalkane. Acid hydrolysis of the phosphorus-containing alkylacetamidomalonic esters gave the required compounds.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2590–2595, November, 1989.     

Heterocyclization of quinazol-2-ylguanidines. 1. Reaction with amino acids

Condensation of 6(7)-R-4-methylquinazol-2-ylguanidines with -amino acids produces 2-hydroxyimidazoles; with anthranilic acid, the corresponding 4-hydroxyquinazolines.Voronezh State University, Voronezh 394693, Russia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 934–936, July, 1999.     

Derivatives of heterocyclic α-iminocarboxylic acids. 1. Syntheses of hydrazides of heterocyclic α-iminocarboxylic acids and their hydrazones

By the interaction of esters of L-proline, L-thioproline, pipecolic acid, and tetrahydro-1,4-thiazine-3-carboxylic acid with hydrazine, the corresponding hydrazides were obtained, which react with equimolar quantities of carbonyl compounds to form hydrazones consisting of mixtures of rotational isomers relative to the amide bond.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1277–1282, September, 1993.     

Aromatization of aliiphatic compounds1. o- and m-tolylacetic acids.

The title compounds were obtained when the reaction products of formaldehyde with tetrahedydrobenzofuranones were treated with PyHCl.     

Thermodynamic models of aqueous solutions containing inorganic electrolytes and dicarboxylic acids at 298.15 K. 1. The acids as nondissociating components

Atmospheric aerosols contain a significant fraction of water-soluble organic compounds, including dicarboxylic acids. Water activities at approximately 298.15 K (including data for highly supersaturated solutions) of oxalic, malonic, succinic, glutaric, maleic, malic, and methyl succinic acids are first correlated as a function of concentration, treating the acids as nondissociating components. Methods proposed by Clegg et al. (J. Aerosol. Sci. 2001, 32, 713-738), and by Clegg and Seinfeld (J. Phys. Chem. A 2004, 108, 1008-1017) for estimating water activities and solute activity coefficients in aqueous mixtures containing both electrolytes and uncharged solutes are then evaluated from comparisons with literature data. These data include water activities, solubilities, and determinations of the eutonic points of solutions containing up to five acids, and solutions containing one or more acids and the salts (NH(4))(2)SO(4), NH(4)NO(3), or NaCl. The extended Zdanovskii-Stokes-Robinson approach of Clegg and Seinfeld yields the more accurate predictions for aqueous mixtures containing dicarboxylic acids only, and for aqueous mixtures of the acids and salts (though by a lesser margin). A number of hybrid modeling approaches, which contain elements of both methods, are outlined.     

Gas-liquid chromatography of thioesters of perfluorocarboxylic acids 1. Characteristics of retention

Retention of thioesters of perfluoropentanoic acid C₄F₉C(O)SR was studied by GLC on packed and capillary columns using stationary phases SE-30, SKTFT-50X, XE-60, and Carbowax 20M. The retention indices of these compounds were calculated, and their relationship with the structure of the compounds and the conditions of the analysis were established. Translated fromIzvestiya Akademii, Nauk. Seriya Khimicheskaya, No. 5, pp. 984–986, May, 1997.     

Diastereoselective synthesis of 1-benzyltetrahydroisoquinoline derivatives from amino acids via 1,4 chirality transfer. Part 1

[structure: see text]. L-(-)-phenylalanine, L-(+)-valine, and L-(-)-proline were used in the diastereoselective synthesis of benzyltetrahydroisoquinoline derivatives.     

A novel rearrangement reaction. A single-step conversion of tetrahydro-1-isoquinolinecarboxylic acids into 1-isoquinolones

The preparation of 2-acyl-6,7-dimethoxy-1,2,3,4-tetrahydro-1-isoquinolinecarboxamides is described. The mixed anhydride of 2-acyl-6,7-dimethoxy-1,2,3,4-tetrahydro-1-isoquinolinecarboxylic acid with isobutyl chloroformate was reacted with the corresponding hydrazines at — 10, — 15°. Besides those compounds, isoquinolones occur through a new side reaction. The structure of those products was established by ¹³C and ¹H nmr and mass spectroscopy. A possible mechanism of the reaction is discussed.