Sodium Methoxide, 0.5 M Methanolic Solution

1982 ◽  
Vol 47 (3) ◽  
pp. 994-999 ◽  
Author(s):  
Hubert Hřebabecký

4-β-D-Ribofuranosyl-1,2,4-triazin-3,5(2H,4H)-dione (IX) and 4-β-D-ribofuranosyl-6-methyl-1,2,4,-triazin-3,5(2H,4H)-dione (XI) were prepared by cyclization of (Z)-4-β-D-ribofuranosyl-semicarbazones of methyl glyoxylate (VI) and methyl pyruvate (VIII) in the methanolic solution of sodium methoxide. A mixture of (E)- and (Z)-ribosylsemicarbazones III and IV was prepared by condensation of the ribosylsemicarbazide I with methyl dimethoxyacetate and a mixture of (E)-and (Z)-isomers V and VIII was obtained on condensation of I with methyl pyruvate. The (Z) isomer VI was prepared on acid-catalyzed isomerisation of the (E)-isomer III while the (Z)-isomer VIII was obtained on the UV-irradiation of isomer V.


2005 ◽  
Vol 58 (7) ◽  
pp. 560 ◽  
Author(s):  
Mitsuhiro Okimoto ◽  
Kaori Numata ◽  
Kenta Tomozawa ◽  
Takamasa Shigemoto ◽  
Masayuki Hoshi ◽  
...  

Several dibenzoylbenzene dihydrazones were electrochemically oxidized into the corresponding bis-dimethyl acetals in a methanolic solution containing sodium methoxide and a catalytic amount of KI. During electrolysis, the anolyte exhibited a characteristic deep purple colour, which strongly suggests the formation of a diazo compound as an intermediate. Such intermediates have been isolated in the electrooxidation of two dihydrazones.


Author(s):  
Yukiko Sugi

In cultured skeletal muscle cells of chick, one intermediate filament protein, vimentin, is primarily formed and then synthesis of desmin follows. Coexistence of vimentin and desmin has been immunocytochemically confirmed in chick embryonic skeletal musclecells. Immunofluorescent localization of vimentin and desmin has been described in developing myocardial cells of hamster. However, initial localization of desmin and vimentin in early embryonic heart has not been reported in detail. By quick-freeze deep-etch method a loose network of intermediate filaments was revealed to exist surrounding myofibrils. In this report, immunocytochemical localization of desmin and vimentin is visualized in early stages of chick embryonic my ocardium.Chick embryos, Hamburger-Hamilton (H-H) stage 8 to hatch, and 1 day old postnatal chicks were used in this study. For immunofluorescence study, each embryo was fixed with 4% paraformaldehyde and embedded in Epon 812. De-epoxinized with sodium methoxide, semithin sections were stained with primary antibodies (rabbit anti-desmin antibody and anti-vimentin antibody)and secondary antibody (RITC conjugated goat-anti rabbit IgG).


1988 ◽  
Vol 53 (3) ◽  
pp. 619-625 ◽  
Author(s):  
Ivan Hemer ◽  
Věra Moravcová ◽  
Václav Dědek

Reaction of 1,4-dibromohexafluoro-2-butene (I) with sodium methoxide, ethoxide or isopropoxide in the corresponding alcohols proceeds with allylic rearrangement under formation of 3-alkoxy-4-bromohexafluoro-1-butenes II-IV. A kinetic study has proven the SN2’ mechanism for reaction of I with potassium phenoxide leading to 4-bromo-3-phenoxyhexafluoro-1-butene (V). Also the reaction of I with ammonia, affording 3-amino-4-bromo-2,4,4-trifluoro-2-butenenitrile (IX), is compatible with the allylic rearrangement by SN2’ mechanism. On the contrary, reaction of I with diethylamine gave no rearrangement product and, after hydrolysis, afforded N,N-diethyl-4-bromo-2,3,3,4,4-pentafluorobutanamide (XVI) and N,N-diethyl-4-bromo-2,3,4,4-tetrafluoro-2-butenamide (XVII) in the ratio 85:15.


1981 ◽  
Vol 46 (2) ◽  
pp. 503-505 ◽  
Author(s):  
Oldřich Kocián ◽  
Miloslav Ferles

The action of malononitrile, ethyl cyanoacetate, dibenzoylmethane and/or p-nitroaniline on compound I in the presence of sodium methoxide gives rise to derivatives of 3-cyano-1-methyl-1,4-dihydroquinoline, II and III


1993 ◽  
Vol 58 (8) ◽  
pp. 1813-1820 ◽  
Author(s):  
Jan Vácha ◽  
Lumír Sommer

The sorption of uranyl ions on columns with the macrophorus hydrophobic sorbent Amberlite XAD 4 modified with 1-(2-pyridylazo)-2-naphthol and sodium diethyldithiocarbamate was examined. Following elution of the uranyl ion with HNO3 (2 - 4 mol l-1) or of the diethyldithiocarbamate UO22+-chelate with a methanolic solution of HCl (0.1 mol l-1), uranium was determined spectrophotometrically with 4-(2-pyridylazo)resorcinol or with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol. The preconcentration of uranium on Amberlite XAD 4 type sorbents is convenient for its spectrophotometric determination in waters.


1997 ◽  
Vol 62 (7) ◽  
pp. 1114-1127 ◽  
Author(s):  
Hubert Hřebabecký ◽  
Jan Balzarini ◽  
Antonín Holý

3'-Chloro and 3'-acetylsulfanyl derivatives of 1-(2-deoxy-4-C-hydroxymethyl-α-L-threo-pentofuranosyl)uracil were prepared by reaction of 2,3'-anhydro-1-{5'-O-benzoyl-4'-C-[(benzoyloxy)methyl]-2'-deoxy-α-L-erythro-pentofuranosyl}uracil (3) with hydrogen chloride and thioacetic acid, respectively. The reaction with hydrogen chloride gave a mixture of N-1 and N-3 substituted uracil derivatives 12 and 14. Reaction of 1-{3-O-benzoyl-4-C-[(benzoyloxy)methyl]-2-deoxy-α-L-threo-pentofuranosyl}uracil (7) with thionyl chloride and subsequent debenzoylation afforded 1-(4-C-chloromethyl-2-deoxy-β-D-erythro-pentofuranosyl)uracil (19). Nucleophilic substitution with lithium thioacetate, followed by deacylation, converted 1-{3-O-benzoyl-4-C-[(benzoyloxy)methyl]-2-deoxy-5-O-p-toluenesulfonyl-α-L-threo-pentofuranosyl}uracil (9) into 1-(2-deoxy-4-C-sulfanylmethyl-β-D-erythro-pentofuranosyl)uracil (21). The obtained thiols were oxidized with iodine or air to give 1,1'-[disulfandiylbis(2,3-dideoxy-4-hydroxymethyl-α-L-threo-pentofuranose-3,1-diyl]di(pyrimidine-2,4-(1H,3H)-dione) (17) and 1,1'-[disulfandiylbis(2,5-dideoxy-4-hydroxymethyl-α-L-threo-pentofuranose-5,1-diyl]di(pyrimidine-2,4(1H,3H)-dione) (22). Reaction of 1-{3-acetylsulfanyl-5-O-methanesulfonyl-4-C-[(benzoyloxy)methyl]-2,3-dideoxy-α-L-threo-pentofuranosyl)}uracil (24) with methanolic sodium methoxide afforded 1-(3,5-anhydro-2,3-dideoxy-4-C-hydroxymethyl-3-sulfanyl-α-L-threo-pentofuranosyl)uracil (25). The same reagent was used in the preparation of 1-(3,5-anhydro-2-deoxy-4-C-hydroxymethyl-α-L-threo-pentofuranosyl)uracil (26) from 1-{4-C-[(benzoyloxy)methyl]-2-deoxy-5-O-p-toluenesulfonyl-α-L-threo-pentofuranosyl}uracil (8). From the series of 4'-substituted 2'-deoxyuridine derivatives, synthesized in this study, solely the 4'-chloromethyl derivative 19 and the oxetane derivative 26 exhibited an appreciable activity against HIV-1 and HIV-2.


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