Synthesis of fluorine-containing alkyl 2-cyano-3-oxocarboxylates. Reactions with nucleophiles

Fluorine-containing alkyl 2-cyano-3-oxocarboxylates were synthesized for the first time by the reaction of ethyl cyanoacetate with fluorine-substituted carboxylic acid halides or alkyl carboxylates. The reactions with hydrazine hydrate, phenylhydrazine, ando-phenylenediamine give hydrazinium (ammonium) enolates or products of acid decomposition. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1961–1965, October, 1999.     

Reactions of 1-aryl(alkyl)-3-ethoxalyl-5,6,7,8-tetrafluoro-1,4-dihydrocinnolin(quinolin)-4-ones with aromatic dinucleophiles

The title compounds react with o-phenylenediamine and o-aminophenol at the ethoxalyl fragment to form heteryl-substituted quinoxalones and benzooxazinones, respectively. o-Aminobenzenethiol acts as both an S-nucleophile replacing the F atom and an N-nucleophile replacing the carbonyl group in the ethoxalyl fragment. Under more drastic conditions, cyclization proceeds to form benzothiazinones.     

Reactions of alkyl acetone-1,3-dicarboxylates with cyanamide and benzoylcyanamide

The reactions of cyanamide with dialkyl acetone-1,3-dicarboxylates in the presence of nickel acetylacetonate afforded alkyl 2-amino-4-hydroxy-6-oxo-1,6-dihydropyridine-3-carboxylates. The same compounds were obtained by intramolecular cyclization of adducts of acetone-1,3-dicarboxylates with benzoylcyanamide under the action of sodium alkoxides. Dedicated to Academician N. K. Kochetkov on the occasion of his 90th birthday. __________ Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1304–1306, May, 2005.     

5,6,7,8-Tetrafluoro-4-hydroxycoumarin derivatives in reactions with o-phenylenediamine

The reactions of 5,6,7,8-tetrafluoro-4-hydroxycoumarin derivatives with o-phenylenediamine occur with pyrone heterocycle cleavage and formation of substituted benzodiazepin-2-ones. 5,6,7,8-Tetrafluoro-4-hydroxycoumarin affords 4-(3,4,5,6-tetrafluoro-2-hydroxyphenyl)-2,3-dihydro-1H-1,5-benzodiazepin-2-one, 3-acetimidoyl-5,6,7,8-tetrafluoro-4-hydroxycoumarin produces 3-(3,4,5,6-tetrafluoro-2-hydroxybenzoyl)-4-methyl-1,2-dihydro-1H-1,5-benzodiazepin-2-one, and 3-acetyl-5,6,7,8-tetrafluoro-4-hydroxycoumarin yields both these heterocycles.     

邻苯二胺合钴氧合反应的研究Ⅰ 水溶液中配合物及其氧合配合物稳定常数的测定

自１９３８年Tsumaki报道犤１犦氧载体以来，这方面的研究已有很大进展犤２犦，只是理论研究居多。氧载体的氧合常数是氧载体研究中的一个重要参数，它的测定是氧载体研究中的一项重要内容，用pH电位法测定氧载体的氧合常数已有研究报道犤２～４犦，作者在研究中发现，邻苯二胺合钴（o－Phdn－Co）配合物在固相和水溶液中与O２反应时表现出很大差异，其反应产物的组成比分别为液相配合物Co∶O２＝２∶１，而固相配合物Co∶O２＝１∶２，为究其成因和进行理论探讨，有必要先测定其氧合常数。由于o－Phdn－Co配合物的配位常数也未见文献…     

Synthesis of some new biologically active coumarin derivatives

The reaction of 4-hydroxycoumarin in toluene with a variety of aromatic binucleophilic compounds has been studied. 3-(Dimethylaminomethylene)chromane-2,4-dione was used as a key intermediate for the preparation of bis[N-(4-oxocoumarinylmethylene)]-1,4-diamines. Alternative synthetic procedures and antibacterial activity data of some of the new compounds are given. Published in Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 361–366, March, 2006.     

Reactions of N,N-(dialkyl)arylthioacetamides with dialkyl acetylenedicarboxylates

2-(Alkoxycarbonylmethylidene)-4-aryl-5-(dialkylamino)thiophen-3(2H)-ones were synthesized by condensation of N,N-(dialkyl)arylthioacetamides with dialkyl acetylenedicarboxylates. Intermediate substituted vinylic sulfides were isolated. When heated or in the presence of an acid or a base, they undergo cyclization into thiophenes.     

Synthese,Kristallstruktur und Konformation von N2-Dibenzyl-N1-t-butoxycarbonylhydrazin

Summary The synthesis and the crystal structure of N²-dibenzyl-N¹-butoxycarbonyl hydrazine are reported. The compound was prepared from commercially availablet-butyl carbazate. It crystallizes in the triclinic space group P 1 witha=5.479(1) Å,b=9.559(1) Å,c=9.748(1) Å,a=63.81(1)°, =87.52(1)°, =74.07(1) Å,Z=1,D=1.18 g/cm³. The structure was solved by direct methods and refined toR=0.0329.

     

Reactions of 2-polyfluoroalkylchromones with aliphatic diamines

2-Polyfluoroalkylchromones react with aliphatic 1,2-diamines to give 2,3-dihydro-1H-1,4-diazepines. A similar reaction with 1,3-diaminopropane yieldsN,N′-trimethylenebis(2-hydroxyacetophenomines) as a result of scission of the original chromones. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 817–819, April, 1999.     

Reactions of N"-acyl- and N"-tosyl-substituted hydrazides of 2-aminobenzoic acid with carbonyl compounds

The reactions of N"-acyl and N"-tosyl-substituted hydrazides of 2-aminobenzoic acid with aliphatic, aromatic, and heterocyclic aldehydes or aliphatic ketones afforded 3-acyl- and 3-tosylamido-1,2-dihydroquinazolin-4-one derivatives, respectively. The structures of the reaction products were established by NMR spectroscopy and X-ray diffraction analysis.     

Reactions of methyl 1-acetylenyl-9,10-anthraquinone-2-carboxylates with hydrazine

Methyl 1-acetylenyl-9,10-anthraquinone-2-carboxylates react with NH₂NH₂ in ethanol at 80°C to give commensurable amounts of substituted 7H-dibenzo[de,h]quinolin-7-ones and 3,4-dihydro-3-aminonaphtho[2,3-f]isoquinoline-4,7,12-triones. The main, route of the reaction apparently includes nucleophilic addition of the reagent to the triple bond of the ester followed by intramolecular cyclization of the adduct with either the carbonyl or the methoxycarbonyl groups involved. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10 pp. 2031–2035, October, 1998.     

Reactions of 4-morpholino-1,2-naphthoquinone with enamines ando-phenylenediamine

The reactions of 4-morpholino-1,2-naphthoquinone with enamines, cyclohexanone derivatives, afford 7a-amino-5-morpholinohexahydrobenzo[b]naphtho[1,2][1,4]dioxines, while the reaction witho-phenylenediamine yields 5-morpholinobenzo[a]phenazine. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 729–732, April, 2000.     

Molecular and crystal structure of 2-benzylidene-6-furfurylidene-cyclohexanone

Single crystal X-ray diffraction has been used to find out that 2-benzyliden-6-furfurylidene-cyclohexanone has the E,E-configuration and s-cis-conformation of the furfurylidene fragment. The furfurylidene substituent and the carbonyl group exhibit the utmost conjugation; the conjugation in the benzylidene fragment is not perfect.     

Reactions of aminophenols with formaldehyde and hydrogen sulfide

The reaction of m-aminophenol with CH₂O and H₂S (1: 2: 1 ratio) afforded 2, 12-dioxa-4, 14-dithia-6, 16-diazatricyclo[15.3.1.1^7,11]docosa-1(20), 7(22), 8, 10, 17(21), 18-hexaene in ∼9% yield. Aminophenol o-and p-isomers react with CH₂O and H₂S (1: 3: 2) to form 2-and 4-[4H-1,3,5-dithiazin-5(6H)-yl]phenols in 86 and 71% yields, respectively. In the crystal structure of the latter, molecules contain dithiazine cycles in the chair conformation with the axial hydroxyphenyl group. Molecular packing represents a combination of molecules forming chains due to the OH...S intermolecular hydrogen bond. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 305–308, February, 2006.     

A Facile Synthesis of Substituted Benzodiazepines Using Solid Support

An easy and convenient synthetic procedure for the preparation of benzodiazepines by coupling microwaves with the solvent technique have been elaborated.     

Reactions of 2-polyfluoroacylcyclohexanones with 1,2-diaminoarenes

Reactions of 2-polyfluoroacylcyclohexanones with 1,2-diaminoarenes yield, depending on the reaction conditions, various 2-polyfluoroalkyl-substituted benzimidazoles. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 562–565, March, 1999.     

o-benzoquinone photoreduction products in the presence of N,N-dimethylanilines

Photoreduction of o-benzoquinones in the presence of para-substituted N,N-dimethyl-anilines under irradiation at λ ≥ 500 nm affords pyrocatechol monoethers of the 2-(amino-methoxy)phenol type. In the subsequent dark reaction, these monoethers undergo quantitative decomposition by a heterolytic mechanism to give the corresponding pyrocatechols and nitrogen-containing compounds. The rate of this decomposition decreases with decreasing size of the substituent at the position adjacent to the ether bond that is formed upon photoreduction. The redox characteristics of such pyrocatechol monoethers can serve as the criterion of their stability. A weakening of the electron-withdrawing properties of quinones and the electron-donating properties of amines leads to an increase in stability of their reaction products. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1528–1535, September, 2006.     

Enzyme-catalyzed reaction of OPD-H202-HRP voltammetric enzyme-linked immunoassay system

Enzyme-catalyzed reaction of o-phenylenediamine (OPD)-H_z0₂-horseradish peroxidase (HRP) voltammetric enzyme-linked immunoassay system has been studied in detail with electrochemical analysis, high performance liquid chromatography (HPLC), ultraviolet/visible (UV/Vis) spectroscopy, infrared (IR) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy. The pure product of H₂0₂ oxidizing OPD catalyzed by HRP was prepared with chemical method. The experimental results of voltammetry and HPLC indicate that only one product of enzyme-catalyzed reaction has been obtained under the selected enzyme-catalyzed reaction conditions. Identifications by UV/ Vis spectrum, IR spectrum and¹³C NMR spectrum show that the product is 2,3-diaminophenazine. The processes of the enzyme-catalyzed reaction and the electroreduction of the product of the enzyme-catalyzed reaction are described. Project supported by the National Natural Science Foundation of China