4-Amino-δ2-1,2,4-oxadiazolines

Reaction of 4-nitrobenzonitrile N-oxide with acetone azine and the dimethylhydrazones of acetone, acetaldehyde, and glyoxal affords the hitherto unknown 4-amino-²-1,2,4-oxadiazolines. The reaction with acetone methylhydrazone also gives a 1,2,4,5-oxatriazine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 262–264, February, 1991.     

Cyclocondensation of 2-Amino-1,3,4-thiadiazoles with β-Sulfonylvinyltrifluoromethyldiols

A series of CF₃-containing 6,7-dihydro-5H-[1,3,4]thiadiazolo[3,2-a]pyrimidin-7-ols was obtained by the interaction of 2-amino-1,3,4-thiadiazoles with -sulfonylvinyltrifluoromethyldiols and their stereochemistry was established. The structure of 5-(phenylsulfonyl)-7-(trifluoromethyl)-6,7-dihydro-5H-[1,3,4]thiadiazolo[3,2-a]pyrimidin-7-ol was confirmed by X-ray crystallography.     

2-Amino-8-naphthoI-6-sulfons?ure (I) und 2-Amino-5-naphthol-7-suIfons?ure(II)

Ohne Zusammenfassung     

Synthesis and Crystal Structure of 2-Amino-1, 1-diferrocenylethanol

2-Aminoalcohols are useful intermediates in organic chemistry, for example, they serve for the synthesis of various heterocycles1, chelate complexes2, and for the ring expansion of cycloalkanones3. 2-Aminoalcohols containing ferrocene as bidentate ligand may be converted into multinuclear compounds. Several methods for the preparation of 2-aminoalcohols have been developed including reduction of the trimethylsilyl cyanohydrins4 or β-nitromethyl alcohols5 and treatment of the epoxides with a…     

Étude de la phényl-2 oxine et de ses chélates: Constantes de dissociation de la phényl-2 oxine

The authors determined, by spcctrophotometric and potentiometric methods, the ionization constants of 2-phenyl-8-quinolinol in hydroalcoholic solutions.     

Den papierchromatographiscben Nachweis von Di?thyldithioacetalen von 2-Amino-2-desoxyhexosen, Urons?uren und neutralen Monosacchariden

Ohne Zusammenfassung     

3-Amino-5-pyrazolon neben Cyanessigs?urehydrazid

Ohne Zusammenfassung     

A Novel Synthesis of 2-Amino-2-deoxy-D-gluconic Acid and Its Complexation with Cu（Ⅱ） in Alkaline Medium

A novel synthesis of the functional carbohydrate 2-amino-2-deoxy-D-gluconic acid was introduced and itscomplex formation with Cu(Ⅱ)was investigated to obtain the stability constant for its further applications to thefood and pharmaceutical industries.The equilibrium was investigated by spectrophotometric measurements andprocessed by dual-series linear regression method.Results:the yield of 2-amino-2-deoxy-D-gluconic acid is 70%.The complexation molar ratio is 1:2,the molar apsorptivity of the complex is 39.906 L·mol~(-1)·cm~(-1) at 630 nm,and the stability constant β_n is 6.24×10~5.     

Copper Bromide–Catalyzed C-Alkylation of 2-Amino-1,4-Naphthoquinone: New Synthesis of 1-Azaanthraquinones

Copper(I) bromide catalyzes the regioselective Michael addition reaction of 2-amino-1,4-naphthoquinone (5) with methyl vinyl ketone and 2-propenal to provide easy access to C-alkylated quinone derivatives, useful precursors of 1-azaanthraquinones.     

Synthesis of New Nitroamino-Containing 1,2,4-Triazines by Reaction of 1-Amino-2-nitroguanidine with α-Diketones

The reaction of 1-amino-2-nitroguanidine with α-diketones (butane-2,3-dione and 1,2-diphenylethanedione) produced new specimens of nitroamino-containing 1,2,4-triazines. The structure of the synthesized compounds of linear and heterocyclic series was confirmed by ¹H, ¹³C{¹H} NMR, IR, and UV spectra.     

Über den Nachweis und die Bestimmung des Arzneimittels 2-Amino-4-methyl-pyridin (I)

Analytical and Bioanalytical Chemistry -     

2-Amino-4,4-disubstituted-5-carboxymethyl-Δ2-1,3,4-oxadiazolin-4-ium chlorides and their recyclization in acetic anhydride

2-Methylamino-4,4-disubstituted-5-carboethoxymethyl-²-1,3,4-oxadiazolin -4-ium chlorides were obtained from the reaction of 1,1-disubstituted-4-methylsemicarbazides with ethyl propiolate in the presence of hydrochloric acid. After hydrolysis of the ester these chlorides recyclize in acetic anhydride to 1-substituted-3-acetoxy-1H-pyrazoles. The difference in the direction of ring opening with acetic anhydride in the betaines of 1,3,4-oxadiazolin-5-acetic acids and their thia-analogs has been demonstrated.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1685–1688, 1992.     

Visible-Light-Mediated Self-Sensitized Oxidative and Regioselective C(sp2)−H Selenylation and Sulfenylation of Substituted 2-Amino-1,4-Naphthoquinones

A photochemical method based on visible-light (white LEDs/sunlight) irradiation has been developed for the regioselective and oxidative C(sp²)−H selenylation and sulfenylation of substituted 2-amino-1,4-naphthoquinones under oxygen atmosphere. The photochemical process does not require any external photoredox catalysts. The other notable advantages of this protocol are metal-free synthesis, visible light/sunlight as energy sources, good substrate scope, and moderate to good yields (41–91 %) with high regioselectivity.     

Synthesis and Crystal Structure Analysis of 2-Amino-4,6-bis（diphenoxyl phosphoramide）-1,3,5-triazine

A disubstituted triazine compound, namely, 2-amino-4,6-bis(diphenoxyl phosphorramide)-1,3,5-triazine, which is an inherent flame retardant monomer, was synthesized specifically, and its structure was characterized by using NMR spectrum and X-ray single-crystal diffraction. Unit cell parameters: space group P21/c, Z=4, a=8.7494(15), b=27.518(5), c=12.511(2),β=109.323(16) , Z=4, V=2842.7(9)β3 , Dc=1.380 g/cm3 , F(000)=1224 and Mr=590.46. All the atoms are in the general positions.     

Über die Konfiguration der diastereomerendl-3-Amino-2,3-diphenyl-propansäuren,dl-1-Amino-1,2-diphenyl-3-propanole und deren Derivate

Zusammenfassung Die diastereomerendl-3-Amino-2,3-diphenyl-propansäuren bzw. ihre Ester werden mittels LiAlH₄ in die entsprechendendl-1-Amino-1,2-diphenyl-3-propanole übergeführt. Diethreo-Konfiguration ordnet man dem Diastereomeren zu, das in Lösung vorwiegend in durch eine Wasserstoffbrücke bedingter Ringkonformation vorliegt und dessen N-Benzoylderivat in alkohol. HCl rascher in das O-Benzoylderivat übergeht. Ferner wird der Versuch gemacht, die relative Reaktionsfähigkeit der Diastereomeren auch an Hand derWinstein-Holnessschen Formel (k=N _a·K _a) qualitativ zu bewerten.     

Investigations of the Chemistry of Alkyl Phosphites Toward Nitrogen-Containing Compounds: Efficient Approaches to α-Amino-, β-Amino-, and/or Enaminophosphonates

Abstract

In this study, we report recent investigations of the chemical reactivity of alkyl phosphites, mainly trialkyl and dialkyl phosphites, with molecules containing different nitrogen-containing compounds reported by us and other research groups over the past 25 years. Previous ground-breaking important reports are also considered. The reviewed investigations in this article are grouped according to only the type of the nitrogen-functional groups [amines (primary, secondary, and tertiary amines), imines, amides, thioamides, nitriles, isocyanates, isothiocyanates, oximes, hydrazones, diazo, and azides] and not according to the site of attack or the final products. Furthermore, the present review article focuses on the synthesis of α-amino-, β-amino-, and/or enaminophosphonates. These compounds have important roles in pharmaceutical chemistry.