Conversion of N-(1-oximino-1-phenylpropyl-2)-α-phenylnitrone into imidazole N-oxide derivatives

Treatment of N-(1-anti-oximino-1-phenylpropyl-2)--phenylnitrone with benzoic anhydride in benzene leads to simultaneous formation of benzoyl derivatives both of the corresponding nitrone and of 1-hydroxymethyl-2, 4-diphenyl-3-imidazoline-3-oxide. Treatment of the latter with hydrogen chloride led to the isolation of 5-methyl-2, 4-diphenylimidazol-3-oxide. Its isomer 4-methyl-2, 5-diphenylimidazol-3-oxide is formed by the action of HCl on syn and anti isomers of N-(1-oximino-1-phenylpropyl-2)--phenylnitrone. IR and UV spectra are used to determine the structures of the compounds, which are confirmed by synthesis.     

Synthesis and properties of substituted 2-imidazolidinones

4-Hydroxy- and 4-hydroxylamino-1-hydroxy-3-aryl-5,5-dimethyl-2-imidazolidinones, respectively, were obtained by treatment of N-arylcarbamoyl derivatives of N-(1-oximino-2-methyl-2-porpyl)hydroxylamine with acids and alkalis. 4-Hydroxylaminoimidazolidinones react with p-nitrobenzaldehyde to give nitrones and are converted in acidic media to 4-hydroxy derivatives, which by the action of methanol in the presence of p-toluenesulfonic acid give 4-methoxy-2-imidazolidinones. Acylation and alkylation of 4-hydroxy- and 4-methoxy-2-imidazolidinones take place at the hydroxy group attached to N(₁).Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1255–1261, September, 1976.     

Reduction of 4H-imidazole N-oxides with sodium borohydride

The reduction of derivatives of 4H-imidazole N-oxides with sodium borohydride leads, depending on the presence and position of an N-oxide group, to 1-hydroxyimidazoline or imidazolidine derivatives. Under the same conditions 4H-imidazole N,N-dioxides form 1,3-dihydroxyimidazolidines. The reduction of 1-hydroxy-2,4,5,5-tetramethyl-3-imidazoline 3-oxide leads to N-(3-oximino-2-methyl-2-butyl) ethylhydroxylamine. It was observed by UV spectroscopy that 1-hydroxy-2-imidazolines exist in a tautomeric equilibrium with 2-imidazoline 3-oxides.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1557–1561, November, 1976.     

New example of the dimroth rearrangement. Intramolecular cyclization of acyl derivatives of anthranilic acid nitrile

A new example of the Dimroth rearrangement in which 4-amino-1H-quinazolin-2-one 3(N)-oxide undergoes isomerization to 4-oximino-1H, 3H-quinazolin-2-one was observed. It is shown that the thermal cyclization of N-(2-amidoximophenyl)ureas and carbamates leads to the production of 4-amino-1H-quinazolin-2-one 3(N)-oxides, while their O-carbamoyl derivatives give 4-oximino-1H, 3H-quinazolin-2-one and 5-oxo-²-1,2,4-oxadiazolino[c3,4]-1H,3H-quinazolin-2-one.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1264–1266, September, 1981.     

Crystal and Molecular Structure of 4-Nitro-2-oximino-3-phenylamino-3-thiolene-1,1-dioxide

The present publication reports the results of X-ray diffraction (XRD) analysis of 4-nitro-2-oximino-3-phenylamino-3-thiolene-1,1-dioxide crystals (I). The synthesis and the useful properties of this class of compounds are reviewed in [1]. It is noteworthy that previously [2] an X-ray structure analysis has been performed for another compound from this class, 3-methyl-4-nitro-2-oximino-3-thiolene-1,1-dioxide (II), which was assumed to exist in nitrone form. The XRD data for compound I disprove this assumption.     

Imidazolyl derivatives of the chroman ring 3

The synthesis of 2-methyl-3-(1-methyl-1H-imidazol-2-yl)-4H-1-benzopyran-4-ones 4 is described starting from 2-acetoxybenzoyl chlorides and 1,2-dimethylimidazole. Chromones 4 undergo alkaline ring opening to the corresponding 1-(2-hydroxyphenyl)-2-(1-methyl-1H-imidazol-2-yl)ethenols 5 which give ring closure to 2-substituted 3-(1-methyl-1H-imidazol-2-yl)-4H-1-benzopyran-4-ones or 2,3-dihydro-3-(1-methyl-1H-imidazol-2-yl)-4H-1-benzopyran-4-ones. The corresponding chromanols and chromenes can be easily obtained from chromones 4 .     

Synthesis of N-tetrahydropyranyl-S-methylmethioninesulfonium salts

D,L-Methionine reacts in alkaline medium with 4-methyl-3,4-epoxytetrahydropyran via the amino group to form, in accordance with the Krasusskii rule, an oxirane ring opening product, namely N-(4-hydroxy-4-methyl-3-tetrahydropyranyl)-D,L-methionine. N-(4-Hydroxy-4-methyl-3-tetrahydropyranyl)-S-methylmethioninesulfonium salts are synthesized in high yields by methylating the latter then treating it with organic or inorganic acids.Bashkir State University, Ufa. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 597–600, May, 1994. Original article submitted February 10, 1994.     

Reaction of α-chloro-α-isonitrosoacetone with aminopyridines

2-Amino, 2-amino-3-methyl-, and 4-aminopyridine react with -chloro--isonitrosoacetone at the heteroring nitrogen atom to give salts, which are converted to imidazo[1,2-a] pyridines or, in the case of 4-aminopyridine, to 1-(1-oximino-2-oxopropyl)-4-pyridoneimine when they are treated with alkali. Acetylpyridylurea was obtained from chloroisonitrosoacetone and 2-aminopyridine in pyridine.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1525–1529, November, 1978.     

SYNTHESIS OF NEW 8-METHOXY-4-METHYL-3-(N-[2′-AMINO-(1′,3′,4′)THIA/OXA-DIAZOL-5′-YL]-SUBSTITUTED METHYL)-AMINO THIOCOUMARINS

8-Methoxy-4-methyl-3-(N-[2′-amino-(1′, 3′,4′)thia/oxa-diazol-5′-yl] substituted methyl)-amino thiocoumarins 6(a–f) and 7(a–f), were synthesized by using the unreported 8-methoxy-4-methyl-3-[N-(2′-oxo-2′-methoxy-1′-substituted ethan-1′-yl) amino thiocoumarins as key intermediates.     

Synthesis of novel pyrimidine derivatives with (pyridin-3-ylmethyl)thio and phenylamino moieties and evaluation of their antifungal activity

A series of novel pyrimidine derivatives with (pyridin-3-ylmethyl)thio and phenylamino moieties were synthesized from ethyl acetoacetate, thiourea, 3-pyridinylmethyl chloride hydrochloride, and substituted anilines by multi-step reactions. The structures of the target compounds were characterized by IR, ¹H NMR, ¹³C NMR and elemental analysis. The in vitro antifungal activities against Botrytis cinerea and Sclerotinia sclerotiorum were evaluated. The result showed that N-phenyl-6-methyl-2- ((pyridin-3-ylmethyl)thio) pyrimidin-4-amine (4a) displayed high inhibition activity against Botrytis cinerea with 87.5%inhibition at 100 µg/mL; 4a, and N-(4-isopropylphenyl)-6-methyl-2-((pyridin-3-ylmethyl)thio)pyrimidin-4-amine (4c), N-(4-methoxyphenyl)-6-methyl-2-((pyridin-3-ylmethyl)thio)pyrimidin-4-amine (4d) and N-(2-hydroxy-5-chloro)-6-methyl-2-((pyridin-3-ylmethyl)thio)pyrimidin- 4-amine (4h) exhibited sufficient activities against Sclerotinia sclerotiorum with 86.6% –93.7% inhibitions at the same concentration.     

Selective monodeoxygenation of quinoxaline-amino acid and ester dioxides

Trimethyl phosphite selectively removes the N-1-oxygen in N-(3-methyl-2-quinoxaloyl) L-α-amino ester-1,4-dioxides, whereas it removes the N-4-oxygen in the corresponding series of dioxides lacking the C₃-Me. This selectivity reversal reflects the relative strength of the intrahydrogen-bridging to the N-1-oxygen. The monoxides having the favourable N-oxygen are not reduced to the quinoxalines, implying that the reagent requires doubling of the N-oxide function for deoxygenation. However, alkaline sodium dithionite removes the N-1-oxygen in both series of the amino acid-dioxides, as well as in the parent quinoxaline-2-carboxylic acid-dioxides, a result that contradicts the report stating removal of the N-4-oxygen. The N-oxygenated quinoxalinium ion ($\text{m}\text{e}$ 145 or 159) prevails in the MS of the 4-oxides, but it is not observed (<1%) for the isomeric 1-oxides. ¹H NMR, ¹³C NMR and UV spectral data also offer diagnostic criteria for differentiation between the isomeric 1- and 4-oxides. Aryl-heteryl “interaction” (as revealed by ¹H NMR, though not by ¹³C NMR in the aromatic amino ester dioxides) is not manifested in the corresponding monoxides.     

Reactions with diazoazoles. Part VI. Unequivocal synthesis of 3-methyl-3h-azolotetrazoles. Correction of the formerly described 3-methylazolotetrazoles in favour of mesoionic 2-methylazolotetrazoles

3-Methyl-3H-pyrazolo[1,5-d]tetrazoles 2 and 3-methyl-6-phenyl-3H-1,2,4-triazolo[1,5-d]tetrazole (4) have been unequivocally synthesized by annulation of the tetrazole moiety to the pyrazole resp. 1,2,4-triazole system. The constitution of some N-methyl substituted azolotetrazoles, formerly described as 3-methyl-3H-pyrazolo[1,5-d]tetrazoles 2, 3-methyl-6-phenyl-3H-1,2,4-triazolo[1,5-d]tetrazole (4) and 1-methyl-6-phenyl-1H-1,2,4-triazolo[4,3-d]tetrazole (5), has to be revised in favour of the corresponding mesoionic 2-methyl derivatives 2′, 4′, 5′. The structures of 3-methyl-3H- as well as of 2-methyl-2H-pyrazolo[1,5-d]tetrazole derivatives 2a, 2c, 2′a have been determined by X-ray analyses. The azapentalenic system is aromatic in all three measured compounds and mesoionic in the case of the 2-methyl-2H- substitution pattern. The phenyl and ester substituents are coplanar with the azapentalene system. 3-, 2-, and 1-Methylpyrazolo[1,5-d]tetrazoles exhibit different behaviour when allowed to react with stannous chloride or sodium ethoxide. Azolotetrazoles with a methyl substituent at N-1, N-2 or N-3 of the tetrazole moiety can be distinguished by a combination of ¹H and ¹³C nmr with respect to the chemical shifts of the N-methyl group and the bridgehead carbon. Results of semiempirical calculations of the pyrazolo[1,5-d]tetrazole anion and of its N-methyl derivatives are discussed.     

Studies on the synthesis of heterocyclic compounds. Part IX. Action of N,N-dimethylformamide dimethylacetal on some oximino-β-dicarbonyl compounds

3-Oximino-2,4-pentanedione ( 1 ) and ethyl 2-oximino-3-oxobutanoate ( 6 ) reacted with N,N-dimethylformamide dimethylacetal (DFDA) to give 1,7-bisdimethylamino-3,5-dioxo-4-methoximinohepta-1,6-diene ( 4 ) and ethyl 5-dimethylamino-2-methoximino-3-oxo-4-pentenoate ( 8 ), respectively. When compounds 4 and 8 were treated with hydrazine hydrate, they gave O-methyldipyrazol-3(5)-ylketoxime ( 5 ) and ethyl 2-methoximino-3(5)-pyrazolylethanoate ( 9 ) together with its corresponding hydrazide 10 , respectively. Upon action of DFDA on 3-oximino-2,4-pentanedione ( 1 ) at -20° an explosive crystalline product was obtained. On the other hand, the reaction of 3-acetoximino-2,4-pentanedione ( 11 ) with DFDA at -20° afforded a product which in ethanol solution, spontaneously deacetylated to give 1-dimethylamino-3,5-dioxo-4-oximinohexa-1-ene ( 13 ). The structures of all the new compounds were assigned on the basis of satisfactory analytical and spectroscopic data.     

Metabolism of a novel antiangiogenic agent KR-31831 in rats using liquid chromatography-electrospray mass spectrometry

KR-31831 ((2S,3R,4S)-4-(((1H-imidazol-2-yl)methyl)(4-chlorophenyl)amino)-6-amino-2-(dimethoxymethyl)-2-methyl-3,4-dihydro-2H-chromen-3-ol) is a novel antiangiogenic agent. In vitro and in vivo metabolism of KR-31831 in rats has been investigated using LC-MS and LC-MS/MS analysis. Incubation of rat liver microsomes and hepatocytes with KR-31831 produced three metabolites (M1-M3). M1, M2, and M3 were identified as N-((1H-imidazol-2-yl)methyl)-4-chlorobenzenamine, (2R,3R,4S)-4-(((1H-imidazol-2-yl)methyl)(4-chlorophenyl) amino)-6-amino-2-(hydroxymethyl)-2-methyl-3,4-dihydro-2H-chromen-3-ol, and N-((2S,3R,4S)-4- (((1H-imidazol-2-yl)methyl)(4-chlorophenyl)amino)-2-(dimethoxymethyl)-3-hydroxy-2-methyl-3,4-dihydro-2H-chromen-6yl)acetamide, respectively, by co-chromatography with the authentic standards and by comparison with product ion spectra of the authentic standards. Those in vitro metabolites were also detected in bile, plasma, or urine samples after an intravenous administration of KR-31831 to rats. The metabolic routes for KR-31381 included the metabolism of acetal group to hydroxymethyl group (M2), N-dealkylation to M1, and N-acetylation at the 6-amino group (M3).     

Volatile coordination compounds of Ni2+ and Co3+ with 1,2-hydroxylaminooximes

Complexes of Ni²⁺ and Co³⁺ with the deprotonated anions of the new ligand N-(3-oximino-2,4-dimethylpentyl-2)hydroxylamine are prepared. The compounds synthesized sublime in vacuum.     

Synthesis of imidazo[4,5-e][1,4]diazepine-8-one

We have developed a method for synthesis of 1-methyl-4,5,7, 8-tetrahydro-6H-imidazo[4,5-e][1,4]diazepin-8-one. We have shown that in intramolecular cyclization of N-(2-hydroxyethyl)- or N-(2-chloroethyl)amides of 1-methyl-4-aminoimidazolyl-5-carboxylic acids it is not the corresponding tetrahydroimidazo[4,5-e][1,4]diazepin-8-ones which are formed but rather the isomeric 4-amino-5-(oxazolin-2-yl)imidazoles.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1203–1206, September, 1993.     

Energetic quaternary salts containing bi(1,2,4-triazoles)

New energetic salts (2, 3, 9, 10, and 11) were synthesized via the protonation of 4,4'-bi(1,2,4-triazole) or N-4-(1,2,4-triazole)-N-3-(4-methyl-1,2,4-triazole)amine with nitric acid or perchloric acid or 5-nitro-tetrazole. The structures of 4,4'-bi(1,2,4-triazolium) nitrate (2), N,N-dimethyl-N'-(5-methyl-tetrazole)methanimidamide (8), and N-4-(1,2,4-triazole)-N-3-(4-methyl-1,2,4-triazolium)amine perchlorate (10) were confirmed by a single-crystal X-ray analysis. The physical properties and heats of combustion of the new ionic salts were measured, and the heats of formation were also determined.     

Formation of 1-(2-aminophenyl)-5-ethoxy-4-methyl-3-phenylpyrazole and 4-methyl-3-phenylpyrazolo-[5,1-b]benzimidazole via an unusual enzotriazole ring opening

Successive treatment of N-[(1-ethoxy)alken-2-yl]benzotriazoles VII with butyllithium and trimethylsilyl chloride in TH-Fat — 78°C followed by refluxing in acidic acetone generated ring-opened 1-(2-aminophenyl)-5-ethoxy-4-methyl-3 phenylpyrazole VIII and 4-methyl-3 phenylpyrazolo[5, 1-b]benzimidazole IX.Published in Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 775–780, June, 1996. Original article submitted May 14, 1996.     

Synthesis of Derivatives of 4-Hydroxy-2-methyl-3-[2-(5-mercapto-1H-1,2,4-triazol-3-yl)ethyl]quinoline and 2-[2-(4-Hydroxy-2-methyl-3-quinolyl)ethyl]-4H-3,1-benzoxazin-4-one

From 4-hydroxy-2-methylquinoline-3-propionyl chlorides hydrochlorides the corresponding thiosemicarbazides were synthesized. The cyclization of the latter both in alkaline and acidic media furnished 4-hydroxy-2-methyl-3-[2-(5-mercapto-1H-1,2,4-triazol-3-yl)ethyl]quinolines. The reaction of the above propionyl chlorides with anthranilic acid afforded the corresponding 2-[2-(4-hydroxy-2-methyl-3-quinolyl)ethyl]-4H-3,1-benzoxazin-4-ones.     

Synthesis and reactions of 1-(2-pyridyl)-3-methyl-4-chloro-5-formyl-6,7-dihydroindazoles

The Vilsmeier formylation of 1-(2-pyridyl)-3-methyl-4-oxo-4,5,6,7-tetrahydroindazole and its 6-phenyl derivative gives 1-(2-pyridyl)-3-methyl-4-chloro-5-formyl-6,7-dihydroindazoles. Reactions of these derivatives with different N- and C-nucleophilic agents, including bisnucleophiles, were studied as a means of obtaining new 4- and 5-functional derivatives of indazole and its condensed systems.Riga Technical University, Riga LV-1658, Latvia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 768–773, June, 1998.