Synthesis of 4-imidazolin-2-ones

The reaction of -bromoketones with CO(NH₂)₂ and AcONH₄ in aqueous acetic acid gave substituted 4-imidazolin-2-ones.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1435–1437, June, 1990.     

The mass spectra of some 4-arylhydrazono-3-methyl-2-pyrazolin-5-ones

The mass spectra of the title compounds, having various substituents on the aryl group are presented and discussed. High resolution mass measurements and metastable ions allow the fragmentation to be rationalized. The system is typified by the occurrence of intense molecular ions and of ions due to consecutive decomposition of the nitrogen-containing part of the molecule. Ions attributable to substituted, aniline-like fragments, and their decomposition products, are also abundant and may be used to identify the aryl group present.     

The mass spectra of 2-aryl-4-arylidene-oxazol-5-ones,and the related thiazol-5-ones and imidazol-5-ones

Examination of the mass spectra of a series of substituted oxazol-5-ones and other related heterocycles showed no evidence of electron-impact induced isomerism. The electron-impact fragmentations of these compounds were characterized by a single dominant fragmentation process.     

1,4,5,6-Tetrahydro-1,2,4-triazin-6-ones and 3-amino-1-imidazolin-4-ones from 2-aminoacylhydrazines

The 2-aminoacylhydrazines form 1,4,5,6-tetrahydro-1,2,4-triazin-6-ones with orthoesters and iminoesters. Benzylidene and isopropylidene derivatives of the 2-aminoacylhydrazines give the corresponding derivatives of 3-amino-1-imidazolin-4-ones with the same reagents.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1388–1391, October, 1991.     

Synthesis of 4-imidazolin-2-ones via the birch reduction of hydantoins

The reduction of 5-(5-methyl-2-furyl)hydantoin to 4-(5-methyl-2-luryl)-4-imidazolin-2-one is described.     

The mass spectrometry of 4-arylquinolizid-2-ones

The fragmentation pathways of ten 4-substituted quinolizid-2-ones were established using exact mass measurement, deuterium labelling and detection of metastable transitions. The base peak for most ketones was formed by cleavage of the C-2? C-3 bond (α to the carbonyl group) and the benzylic C-4? N bond. The decompositions examined were compared with those of the Nuphar alkaloids.     

The mass spectra of potential antidiabetics: 4-Arylhydrazono-3-methyl isoxazol-5-ones and pyrazol-5-ones

The mass spectra of variously substituted 4-arylhydrazono-3-methyl isoxazol-5-ones and pyrazol-5-ones have been examined, and the fragmentation pathways elucidated. The spectra of the former compounds differ from previously reported 4-arylidene derivatives and this difference has been attributed to fragmentation involving the ? NH? N?moiety. The investigation has shown up some interesting ‘ortho effects’ as well as the facile loss of HN?C?NH from N-amidino derivatives of the pyrazol-5-ones.     

2-烷基氨基-3-芳基-5-苄基-1-咪唑啉-4-酮的合成及杀菌活性

咪唑啉酮衍生物;反应;2-烷基氨基-3-芳基-5-苄基-1-咪唑啉-4-酮的合成及杀菌活性     

Mass spectrometric studies of alkyl-, phenyl- and chloropyrimidines

The mass spectra of alkyl- and chloropyrimidines are recorded. A generalised fragmentation mechanism for the derivatives of pyrimidine is proposed. The principle of α-cleavage for heterocyclic compounds as proposed in the previous paper is shown to be valid for pyrimidine derivatives. Electronic structures of some molecular and intermediate ions are calculated by the openshell CNDO/2 and INDO methods.     

Ring closures from eneearbamoyl azides. Syntheses of tetrahydro-3-indazolinones and 4-imidazolin-2-ones

Reaction of phosgene with cyclohexylidene amines gives good yields of (1-eyclohexen-l-yl)-carbamoyl chlorides ( 1 ). Compound 1 can be converted to the corresponding eneearbamoyl azide ( 2 ), which on pyrolysis gives an improved synthesis of 1-substituted-4,5,6,7-tetrahydro-3-indazolinones ( 7 ). When 1 is substituted by an allylic rather than alkyl or aryl group, the major products are 4-imidazolin-2-ones ( 8 ) accompanied by only minor amounts of 7 . The thermolysis reaction has been extended to N-allylcarbamoyl azides in general, thus providing a new and facile synthesis for 1,4-disubstituted 4-imidazolin-2-ones (9). A tentative mechanism is advanced, involving intermediate azide addition to the allylic double bond.     

The mass spectra of some 2- and 4-pyridylethylamines

The mass spectra of some N,N-disubstituted 2-aminoethylpyridines are reported and their principle fragmentation routes analysed.     

Synthesis of 2-imino-4-thiazolines, 2-imino-4-alkoxythiazolidines,thiazoles and 4-imidazolin-2-ones from α-halomethyl ketimines

A variety of heterocycles, including 3,4-disubstituted-2-imino-4-thiazolines, 3,4-disubstituted-4-methoxy-2-iminothiazolidines, 2,4-disubstituted-thiazoles, 2-amino-4-substituted-thiazoles and 1,5-disubstituted-4-imidazolin-2-ones, were synthesized from α-chloromethyl and α-bromomethyl ketimines by condensation with potassium thiocyanate, thiourea, ammonium thiocyanate and potassium cyanate.     

Electron impact studies—LXVII. The mass spectra of alkyl-1,3-dithianes

The mass spectra of 1,3-dithiane, 2-methyl- and 2,2-dimethyl-1,3-dithiane have been studied by ²H labelling and metastable defocusing. The various molecular ions eliminate S₂H. to produce the ions [C₄H₇]⁺, [C₅H₉]⁺ and [C₆H₁₁]⁺ respectively, each of which scramble the hydrogens either before or accompanying further decomposition. Other processes are complex, but parallel those already reported for 2-aryl-1,3-dithianes.