Magnitudes of the inductive effects of the nitro and nitrate groups

Conclusions The value of the induction constant for the nitrate group has been calculated (^*(–CH₂ONO₂)=1.34) and the value of the induction constant of the nitro group has been refined (^*(–CH₂NO₂)=1.73).Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1488–1490, August, 1966.     

Synthesis of bridged cobaloximes

Chloro-pyridino-bis (glyoximato)-cobalt(III) complexes (cobaloximes) have been synthesized in which two corners are connected by a bridge consisting of 10 or 12 methylene groups. These compounds are designed to mimic some important features of the active site of coenzyme B₁₂ dependent enzymes.     

Imidazole derivatives containing potential labile groupings on a nitrogen atom

A number of N-mercaptomethyl- and N-(-mercaptoethyl)benzimidazoles has been synthesized and their properties have been studied.For part I, see [1].     

Imidazole derivatives containing potentially labile groupings attached to N1

A number of 1-aralkylbenzimidazoles, the amination of which with sodium amide gives 1-aralkyl-2-aminobenzimidazoles, were obtained by the reaction of substituted benzyl chlorides or benzhydryl chlorides with benzimidazole or its silver salt. The successful amination of 1-benzhydrylbenzimidazole attests to the insignificant influence of steric effects on the Chichibabin reaction in the benzimidazole series [2]. 1-Methoxymethyl-2-aminobenzimidazole was obtained by the reaction of methoxymethyl chloride with the sodium salt of 2-aminobenzimidazole in absolute dioxane.See [1] for communication V.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 809–811, June, 1972.     

Imidazole derivatives containing potentially labile groupings attached to an N-atom

The action of benzyl alcohol on 2-aminobenzimidazoles in the presence of alkali has given a high yield of a number of 2-benzylaminobenzimidazoles which have been converted subsequently into 2-dibenzylaminobenzimidazoles and 2-benzyliminobenzimidazolines.For part IV, see ¦1¦.     

Halogenation of thenyl and furyl cobaloximes

The reactions of thenyl and furyl cobaloximes with halogens (bromine and chlorine) in acetic acid and chloroform indicate that, CoC bond cleavage occurs in 2-thenyl and 2-furyl case whereas the ring substitution is faster than CoC band cleavage in 3-thenyl and 3-furyl cobaloximes.     

Synthesis of some thienyl-substituted α,β-unsaturated ketones containing a nitro group

A method for the condensation of nitroformylthiophenes with ketones of the aromatic and heterocyclic series by means of ammonium acetate in glacial acetic acid was developed. The method makes it possible to obtain thienyl-substituted , -unsaturated ketones with a nitro group in the heterocyclic ring.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1048–1049, August, 1980.     

Metal nitrate driven nitro Hunsdiecker reaction with α,β-unsaturated carboxylic acids under solvent-free conditions

Hunsdiecker reactions with α,β-unsaturated carboxylic acids were conducted under solvent-free conditions in the presence of a few drops of HNO₃ together with a variety of metal nitrates [Mg(NO₃)₂, Sr(NO₃)₂], Al(NO₃)₃, Ca(NO₃)₂, Ni(NO₃)₂, Cd(NO₃)₂, Zn(NO₃)₂, Hg(NO₃)₂, AgNO₃, ZrO(NO₃)₂, UO₂(NO₃)₂, Th(NO₃)₂] or ammonium nitrate. α,β-Unsaturated aromatic carboxylic acids underwent nitro decarboxylation to afford β-nitro styrenes in moderate to good yields, while α,β-unsaturated aliphatic carboxylic acids underwent decarboxylation to yield the corresponding nitro derivatives.     

Imidazole derivatives

It is shown that 4(5)-(4-alkoxyphenyl)-5(4)-nitroimidazoles are obtained when 4(5)-(4-alkoxyphenyl)imidazoles are refluxed with 3–4 N nitric acid. The use of concentrated nitric acid (d ₄ ²⁰ 1.42, 1.46) leads to di- and trinitro-substituted phenylimidazoles. The mass spectra of the nitro derivatives were studied, and the principles of the fragmentation were ascertained.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1384–1388, October, 1977.     

Tetracyclische Imidazole

2-(Phenacyl)-tetrahydro--carboline (2) was transformed to theE/Z-oximes3 and4 and the isolated species cyclodehydrogenated to the nitrone5 and oxadiazine6. These compounds were dehydrated in acidic medium to the imidazole9.

     

Vibrational spectroscopic study of the nitrate containing hydrotalcite mbobomkulite

Raman spectroscopy has been used to study the nitrate hydrotalcite mbobomkulite NiAl2(OH)16(NO3).4H2O. Mbobomkulite along with hydrombobomkulite and sveite are known as 'cave' minerals as these hydrotalcites are only found in caves. Two types of nitrate anion are observed using Raman spectroscopy namely free or non-hydrogen bonded nitrate and nitrate hydrogen bonded to the interlayer water and to the 'brucite-like' hydroxyl surface. Two bands are observed in the Raman spectrum of Ni-mbobomkulite at 3576 and 3647 cm(-1) with an intensity ratio of 3.36/7.37 and are attributed to the Ni3OH and Al3OH stretching vibrations. The observation of multiple water stretching vibrations implies that there are different types of water present in the hydrotalcite structure. Such types of water would result from different hydrogen bond structures.     

Microwave assisted synthesis of nitro phenols from the reaction of phenols with urea nitrate under acid-free conditions

Urea nitrate was found to be an inexpensive, acid-free, and safe nitrating agent that provides mononitration of phenols and substituted phenols in excellent yields with exclusive ortho-selectivity under microwave irradiation. Microwave assisted reactions reduced the reaction times substantially and enhanced the product yields from good to excellent within shorter reaction times.     

Single- and double-linkage isomerism in a six-coordinate iron porphyrin containing nitrosyl and nitro ligands

Density Functional theoretical calculations confirm the experimental observation that the low-temperature photolysis of (TPP)Fe(NO)(NO2) (as a KBr pellet) results in the generation of linkage isomers involving the axial NO and NO2 groups and suggest the possible formation of the double linkage isomer (TPP)Fe(ON)(ONO). The energy difference between the ground state (porphine)Fe(NO)(NO2) and the double-linkage isomer (porphine)Fe(ON)(ONO) is 1.57 eV, which is comparable to the 1.59 eV calculated previously for the nitrosyl-to-isonitrosyl linkage isomerism in the five-coordinate (porphine)Fe(NO) analogue.     

Thermal and photochemical epimerization/equilibration of carbohydrate cobaloximes

Epimeric carbohydrate alkyl cobaloximes 4:5, 9:10, and 12:13 can be equilibrated thermally or photochemically. In each case, one isomer is strongly favored: exo-3-deoxy-3-pyridyldimethylglyoximatocobalt-1,2:5,6-di-O-isopropylidene-alpha-D-glucofuranose 4 for the 4:5 epimer pair, exo-3-deoxy-3-pyridyldimethylglyoximatocobalt-5-O-carboxymethyl-1,2-O-isopropylidene-alpha-D-xylofuranose 9 for the 9:10 epimer pair, and equatorial 1-deoxy-1-pyridyldimethylglyoximatocobalt-2,3,4,6-tetra-O-benzyl-beta-D-glucopyranose 12 for the 12:13 epimer pair. These data indicate that there is a strong facial preference for the coupling of py(dmgH)(2)Co(*) radicals with alkyl R(*) free radicals, with the preferred kinetic path leading to the more stable product.