Synthesis of N-(N-bromoacetylglycyl)-β-D-glycopyranosylamines,derivatives of monoand di-α-L-fucosylated diand trisaccharides

Russian Chemical Bulletin - N-(N-Bromoacetylglycyl)-β-glycopyranosylamines of diand trisaccharides, namely, α-LFucp-(1→6)-β-D-GlcNAcp-NHCOCH2NHCOCH2Br,...     

Synthesis of 2β, 3β, 14α-trihydroxy-Δ4,7-6-ketosteroids and their derivatives

A scheme using -sitosterol as an example for synthesizing 2, 3, 14-trihydroxy-^4,7-6-ketosteroids and their derivatives from 3-hydroxy-⁵-steroids was developed.Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, 220141, Belarus, Minsk, ul, akad. Kuprevicha, 5/2. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 244–248, May–June, 2000.     

Synthesis of N-β- trifluoroethyl derivatives of maleic and citraconic acids

Summary Halogen derivatives of the N-alkylmonoamides and N-alkylimides of maleic and citraconic acid containing the strongly electronegative group CF₃ in the alkyl radical, previously unreported in the literature, have been synthesized.     

Synthesis and characterization of water-swellableα,β-polyasparthydrazide derivatives

The synthesis of a new crosslinked polymer by reaction of , -polyasparthydrazide and glutaraldehyde is reported. Different crosslinking degrees were obtained by varying the ratio between the aldehyde and the starting polymer. The crosslinked polymer was characterized by water swelling tests and thermal analysis. In particular, the crosslinking density and its effects on the glass transition temperature of the material were studied. Finally, the microstructure of the obtained polymer was observed using scanning electron microscopy.     

Synthesis and characterization of water-swellableα,β-polyasparthydrazide derivatives

, -polyasparthydrazide (PAHy) was crosslinked by glutaraldehyde to form water-swellable materials possessing a three-dimensional molecular network. Different crosslinking degrees were prepared varying glutaraldehyde/PAHy ratio and samples containing 5-fluorouracil were obtained by incorporating the drug into the polymer networks during the crosslinking reaction. All samples were characterized by swelling tests, thermal, x-ray and SEM analysis. Their microstructure was observed through scanning electron microscopy. Furthermore, for samples containing the anticancer drug,in vitro release studies were performed in pH 7.4 buffer solution.     

Synthesis of N-(alkoxycarbonyl or alkoxycarbonyl-methyl-alkoxyphosphonyl)-α-amino-O,O-diphenyl phosphonates and their bioactivities

With phosphoric formic acid (PFA) and its analog,phosphonoacetic acid (PAA),as the lead compounds,α-amino phosphonates were introduced into PFA and PAA.The derivatives oi N-( alkoxycarbonyl-aikoxyphosphonyl)-α-arnino phosphonates (Ⅰ) and N-(alkoxycarbonyl-methyt-alkoxyphosphonyl)-α-amino phosphonates (Ⅱ) with the N-terminal of amino phosphonates bonding to phosphorus atom of PFA and PAA were synthesized via the reaction of the corresponding phosphonyl chloride with a-amino phosphonates in the presence of a base.The 31P NMK spectra of Ⅰ and Ⅱwere determined.It is found that the coupling constants 3Jpp with R3 being alkyl group were lower than those with R3 being (substituted) phenyl,and this result was discussed.The preliminary bioassay showed that some of the compounds Ⅰ and Ⅱhave better activities against tobacco mosaic virus (TMV).The inhibitory was higher than that of DHT (2,4-dioxyhexahydro-1,3,5-triazine).In addition,some of the compounds showed the activity against cancer cells.     

Aryl-ONN-azoxy-α,α-dinitroalkanes and some of their derivatives

Previously unknownN-dinitroalkyl-NNO-azoxybenzenes have been prepared (by nitration ofN-(-hydroximino) alkyl-NNO-azoxybenzenes) and transformed to some derivatives.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1972–1975, November, 1994     

Synthesis and Cyclization of N-(4-Phenoxyphenyl)-β-alanines

We have used the reaction of 4-aminodiphenyl ester with acrylic, methacrylic, crotonic, and itaconic acids to synthesize N-substituted -alanines, which undergo ring closure to form derivatives of dihydropyrimidinedione and 4-carboxy-2-pyrrolidinone. We have studied the reactions of acylation and recyclization of the dihydropyrimidinedione ring, and we have synthesized derivatives of 4-carboxy-1-(4-phenoxyphenyl)-2-pyrrolidinone: arylidene hydrazides, 2[(2-oxo-4-pyrrolidinyl-1-(4-phenoxyphenyl)]benzimidazole.     

Synthesis of N-(methoxycarbonyl or isopropylcarbamoyl- methoxyphosphonyl)-α-amino acid ester and their stereomers

N-(methoxycarbonyl-methoxyphosphonyl)-α-amino add esters (I) were synthesized via the reaction of the corresponding phosphonyl chloride with amino acid ester hydrochlorides in the presence of a base. Compound I was aminated to yield N-(isopropylcarbainoyl-methoxyphosphonyl)-α-amino acid esters (II). With l-amino acids as starting materials, the isomers of products I and II were separated and their configurations were confirmed by the single crystal X-ray diffraction of II.     

Synthesis of furanyl- and triazolyl-containing α-CF3-α-hydroxy acids and their derivatives

Russian Chemical Bulletin - Starting from methyl trifluoropyruvate, α-CF3-substituted α-methoxy-α-(furan-2-yl) acetic acids and their derivatives and also methyl...     

Synthesis of (α-nitroalkyl-ONN-azoxy)furoxan derivatives

The first synthesis of 4-(α-nitroalkyl-ONN-azoxy)-3-methylfuroxans was accomplished by the reaction of 4-amino-3-methylfuroxans with pseudo nitrols in the presence of dibromoisocyanurate.     

Synthesis of alkyl-α,α-dimethylcyclopropanemethanols and alkylcyclopropyl methyl ketones

Russian Chemical Bulletin -     

3-Amino-4-(α-nitroalkyl-ONN-azoxy)furazans and some of their derivatives

Synthetic procedures towards 3-amino-4-(a-nitroalkyl-ONN-azoxy)furazans and their derivatives involving nucleophilic displacement of the nitro group of 3-nitro-4-(a-nitroalkyl-ONN-azoxy)furazans on treatment with ammonia, primary and secondary amines, including diamines, were developed.     

First Total Synthesis of 3α,4α-Oxidoagarofuran and (-)-3β,4α-Dihydroxy-β-dihydroagarofuran

The first stereoselective total synthesis of (–)-3β, 4α-dihydroxy-β-dihydroagarofuran (1) and 3α, 4α-oxidoagarofuran (2) has been described. The key step is the epoxidation of α-agarofuran (6) with dimethyldioxirane.     

Synthesis of ( )-5α-Hydroxy-β-selinene and (-)-5β-Hydroxy-β-selinene

Eudesmanederivativeshavebeendrawingconsiderableattentionduetotheirwidespectrumofbiologicalproperties,particularlyantifeedant,cellgroWthinhibitoryandplantgroWthregulatingactivitiesl'2.Recently,twoepimericeudesmanederivatives( )-5a-hydroxy-6-selinene1and(-)-56-hydroxy-6-selinene2wereisolated3fromtheaerialpartsofCSubtraPicaFMell.,andtheirstructuresweredeterminedbyspectroscopicmethods.Herein,wereportafacilesynthesisofbothtwodiastereomers1and2from( )-dihydrocarvone3infivesteps,usingtheregioselect…     

3,4-Bis(α-nitroalkyl-ONN-azoxy)furazans and some of their derivatives

Reaction of pseudonitroles and their derivatives with diaminofurazan in the presence of dibromoisocyanuric acid (DBI) resulted in symmetrical 3,4-bis(-nitroalkyl-ONN-azoxy)-furazans or their derivatives. For the synthesis of bis(nitroalkyl-ONN-azoxy)furazans bearing various a-nitroalkyl-ONN-azoxy groups, the method based on the reaction of ??-nitronitroso compounds with 3-amino-4-(nitroalkyl)-ONN-azoxy)furazans (in the presence of DBI) was developed. Synthetic procedures towards aforementioned compounds with nitromethyl-, dibromonitromethyl-, trinitromethyl-ONN-azoxy and other groups were described.     

Synthesis and structures of mono(β-diiminato) copper complexes and their catalytic performances for homo- and copolymerizations of methyl acrylate

A series of mono(β-diiminato) copper complexes bearing different coordinating anions and with different fluorine substitution patterns on the β-diiminato ligands were synthesized. All of the complexes were characterized by physicochemical and spectroscopic methods, and in addition, the structures of two of them were confirmed by X-ray diffraction. The crystal structures revealed a four-coordinate mode around the copper center in a slightly distorted square planar geometry, with the β-diimine and the carboxyl groups coordinated to give six- and four-membered chelate rings. The conjugation of C=C and C=N in the β-diiminato ligands and the resonance between C–O and C=O in the carboxyl groups resulted in extensive delocalization of electrons and the formation of conjugated N–C–C–C–N and O–C–O π-bonds, respectively. When activated by modified methylaluminoxane (MMAO), these complexes can effectively catalyze methacrylate (MA) polymerization with activities up to 54.5 kg/mol Cu h, as well as MA/1-hexene copolymerization with the incorporation of MA over 80 %.     

Synthesis and cyclization of N-(9-alkylcarbazol-3-yl)-β-alanines

The reaction of 3-amino-9-alkylcarbazoles with acrylic and itaconic acids yields N-substituted amino acids, which were converted into derivatives of 4-carboxy-2-pyrrolidinone and dihydropyrimidinedione.Kaunas Technological University 3028 Kaunas, LithuaniaTranslated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1637–1640, November–December, 1999.