Mass spectra of ortho substituted 1-phenyl-2-thioureas

The mass spectra of some 1-(o-alkylphenyl)-2-thioureas have been investigated and deuterium labelling shows that the proton lost in the SH? abstraction originates from the α-hydrogens in the o-alkyl group. The intensity of the fragment ion formed by loss of the o-alkyl group increases with the stability of the corresponding alkyl radical.     

13C NMR spectra of substituted thiacyclohexanes

Conclusions The use of the¹J_CH values permits making an unequivocal assignment of the¹³C signals in the spectra of substituted thiacyclohexanes. The steric arrangement of the substituants in 2,4-disubstituted thianes can be established on the basis of the chemical shift values of the C⁶ nuclei. The obtained data can be used to identify the cyclic organosulfur compounds that are isolated from crude petroleum.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 452–454, February, 1982.     

The NMR spectra of some substituted dibenzothiophenes

In order to use the NMR spectra of dibenzothiophenes to determine the position of substitution, a series of compounds has been prepared, most of which are new while some represent an improved method of preparation of previously reported compounds. With the exception of one, the structures of the compounds prepared were not in doubt, however the splitting patterns and chemical shifts presented here will facilitate future structure determinations of dibenzothiophenes.     

1H NMR spectra of substituted phenazines

The ¹H NMR Spectra of 28 substituted phenazines have been measured and analysed with computer assistance. Substituent increments of chemical shifts were calculated for methoxy, carbomethoxy and methyl derivatives. The influence of these substituents on coupling constants has been examined.     

Preparation and NMR spectra diaminotetraaryloxycyclotriphosphazenes

New diaminotctraaryloxycyclotriphosphazenes N₃P₃(NH₂)₂(OR)₄ were prepared by the reaction between N₃P₃(NH₂)₂Cl₄ and RONa in THF solvent and 31P NMR data showed geminal compounds were formed.     

13C NMR spectra of cyclopropane derivatives. Stereoisomeric substituted 2-phenylcyclopropanes

Proton-decoupled carbon-13 magnetic resonance spectra of a series of cyclopropane derivatives have been studied. For stereoisomeric substituted 2-phenylcyclopropanes a difference between the isomers has been found in the shieldings of the three-membered cyclic carbons as well as in the shieldings of the carbons of the substituents. The chemical shifts have been interpreted on the basis of an additive approach worked out in a study of the spectra of monosubstituted cyclopropanes and substituted 2,2-diphenylcyclopropanes. Some simple rules have been proposed, which are useful in distinguishing stereoisomeric 1,2-disubstiuted cyclopropanes.     

Synthesis of substituted 2-phenyl-6-hydroxyquinazolines

A method was developed for the synthesis of 2-phenyl-6-hydroxy(methoxy)quinazoline and a number of N-substituted 2-phenyl-4-amino-6-hydroxyquinazolines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 418–420, March, 1971.     

Carbon-13, nitrogen-15 and oxygen-17 NMR chemical shifts of substituted 1-phenyl-2-pyrrolidinones

The carbon-13 and nitrogen-15 NMR chemical shifts and the direct carbon—proton coupling constants of 1-phenyl-2-pyrrolidinone and its 2′-methyl, 3′-methyl, 4′-methyl, 2′-chloro, 3′-chloro, 4′-chloro, 3′-methoxy, 4′-methoxy and 4′-nitro derivatives were measured in dimethyl sulfoxide. The oxygen-17 NMR chemical shifts of some of the compounds were determined in acetone.The effect of substituents on the chemical shifts of carbonyl carbons correlates well with the Hammett substituent parameters and the nitrogen chemical shifts seem to follow a similar trend. The variation of the oxygen chemical shift due to the substituents is small. The chemical shifts of aromatic carbons can mainly be derived using the substituent parameters of benzene; some deviation probably due to steric effects is observable, however.     

Crystal and molecular structure of 5,5-dichlormethyl-2-phenyl-1,3-dioxane

All-Union Scientific-Research Institute of Chemical Reagents and Ultrapure Chemical Substances. Ufa Petroleum Institute. Translated from Zhurnal Strukturnoi Khimii, Vol. 29, No. 4, pp. 149–153, July–August, 1988.     

15N NMR study of substituted 2-(phenylamino)-5-phenyl-1,3,4-oxadiazoles

Substituted 2-(phenylamino)-5-phenyl-1,3,4-oxadiazoles were studied by 15N NMR spectroscopy. All signals were assigned on the basis of HMQC and HMBC experiments. Chemical shifts values were correlated with empirical Hammett parameters as well as with calculated electron densities and chemical shieldings.     

Synthesis of 3,5-O-Benzylidene-2-deoxy-L-riboaldose from 5,5-Dihydroxy-2-phenyl-1,3-dioxane

The asymmetric alkylation of 2-phenyl-1,3-dioxan-5-one was achieved via the RAMP-hydrazone. Regeneration of the ketone followed by setreoselective reduction and ozonolysis, gave the protected 2-deoxy-L-ribose, 3,5-O-benzyldiene-2-deoxy-L-erythro-pentoaldose with 98% e.e. Removal of the benzylidene yielded the unnatural 2-deoxy-L-ribose.     

Synthesis and IR spectra of 5-phenyl-2-(1-phenyl-2-trichloroacetylethenyl)pyrrole

5-Phenyl-2-(1-phenyl-2-trichloroacetylethenyl)pyrrole was synthesized by the reaction of 2-phenylpyrrole with 1-phenyl-2-trichloroacetylacetylene on silicon oxide. The structure of an intramolecular proton-transfer H-complex was assigned to the title compound based on analysis of its IR spectra in solutions in the temperature range of 165–298 K. Published inIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 11, pp. 1945–1947, November, 2000.     

Ultraviolet spectra of 2-phenyl-4- and 2-phenyl-5-azaindan-1, 3-diones

The UV spectra of 2-phenyl-4-azaindan-1, 3-dione (I), 2-phenyl-5-azaindan-1, 3-dione (II), and their N-methylbetaines are investigated. 2×10^–5 M aqueous alcoholic solutions of 2-phenyl-4-azaindan-1, 3-dione (I) contain the anionic form (IA), and in solutions of 2-phenyl-5-azaindan-1, 3-dione (II) the betaine form (IIB) is also in equilibrium with the anion (IIA). Solutions of I and II in 0.1 M sulfuric acid are characterized by a wide and rather intense absorption band at about 500 m, indicating the presence of a betaine form (IB and IIB). In 2M hydrochloric acid solution 2-phenylazaindan-1, 3-diones and their N-methylbetaines (III and IV) are protonated at the oxygen atom, giving the enol forms of the N-protonated or corresponding N-methylated 2-phenylazaindandiones.