DMF solution

The benzyl group has been widely used for the protection of hydroxyl functions in carbohydrate and nucleotide chemistry (C.M. McCloskey, 1957 C.B. Reese, 1965 B.E. Griffin, 1966). A common benzylation procedure involves heating with neat benzyl chloride and strong bases. A milder procedure is the reaction in DMF solution at room temperatiue with the aid of silver oxide (E. Reinefeld, 1971). Benzyl ethers are not affected by hydroxides and are stable towards oxidants (e.g. periodate, lead tetraacetate), LiAIH, amd weak acids. They are, however, readily cleaved in neutral solution at room temperature by palladium-catalyzed bydrogenolysis (S. Tejima, 1963) or by sodium in liquid ammonia or alcohols (E.J. Rcist, 1964). 

DMF solutions pORMIC ACID AND DERIVATIVES - DITffiTTTYLFORMAMIDE] (Vol 11) N,2-Dicyanoacetamidate [53557-77-0]... 

Boujlel and Simonet used an electrochemical method to prepare a group of similar compounds, including compound ]5, shown in Eq. (3.41). In a typical case, benzil was reduced in DMF solution at the dropping mercury electrode in the presence of tetrabutylammonium iodide, used in this case as a supporting electrolyte rather than phase transfer catalyst. In the presence of diethylene glycol ditosylate, compound 15 (mp 77— 78°) was isolated in 10% yield. Using the same approach, acenaphthenedione was reduc-tively cyclized with triethylene glycol ditosylate to afford the product (mp 84—85°, 42% yield) shown in Eq. (3.42). 

In a typical experiment, triethylene glycol was treated with two equivalents of sodium toluenesulfonamide in dry DMF solution. After 6 h at reflux, the solution was distilled and product obtained by a standard work-up procedure. By this procedure, 9 was obtained in about 10% yield. The transformation is illustrated below as Eq. (4.10). Note also that Vogtle and his coworkers have also utilized phthalimide as a source of nitrogen in the preparation of such azacrown precursors as H2N(CH2CH2 0)2CH2CH2NH2 In such reactions, a standard hydrazine cleavage was used to remove the phthaloyl residue. 

Perfluoroalkyltin halides can be prepared via oxidative addition of perfluo-roalkyl iodides to tin(II) halides in dimethylformamide (DMF) [12] The per-fluoroalkyltin(IV) dihalide could not be isolated, but in DMF solution, the tin(lV) compound did react with aldehydes and ketones in the presence of pyndine [12] (equation 8) Typical perfluoroalkylcarbinols prepared by this method are shown in Table 1 [12]... 

Slow addition of excess H3PO2 to 1 M DMF solution of substrate at 50°. ... 

A treatment of 2-butyltelluroaniline with an equimolar amount of bromoacetic acid results in spontaneous cyclization of the formed telluronium salt 31 to give 1-butylbenzotellurazinonium bromide 30. That the alkylation occurs at the tellurium and not at the nitrogen atom of 2-butyltelluroaniline has been proved by the isolation of the methyl ester of 31 in 60% yield when the amine was coupled with methyl bromoacetate under the same reaction conditions. Elimination of butyl bromide from 30 readily occurs on heating of its DMF solution leading to 2//-l,4-benzotellurazin-3(4//)-one 32 in 90% yield. 

Bischler-Napieralski reaction of 139 to a 3,4-dihydroisoquinoline, oxidation, dehydrogenation and reduction of the nitro to the amino function gave 140 which was subjected to a Pschorr reaction (Scheme 49). Quaternization was accomplished by methyl iodide to furnish the isoquinolininium salt 141 which underwent an ether cleavage on heating a solid sample or benzene or DMF solution to Corunnine (127) (73TL3617). 

Li et al. [87,88] found that aniline will process the photopolymerization of AN either in N,N-dimethylformamide (DMF) solution or in bulk with a fair rate of polymerization only next to DMT. From UV spectra it is proved that aniline will form a CTC with AN. Using 313-nm radiation that CTC is excited to an exciplex and polymerization proceeds. N-methylaniline will polymerize AN similarly. The following mechanism was proposed ... 

Fibres spun out of copolymers 2 by the wet process from dimethylformamide (DMF) solutions have the following characteristics strength 23-27 g.f./tex (2,5-3 g/denie), elongation 15%. 

The fibres spun from copolymers of AN with 4 formed by the wet process from DMF solutions have satisfactory physico-mechanical properties. 

Investigations of PAN reduction in DMF solution in the presence of Raney nickel, sodium hyposulfite, acetic acid, pyridine, and water at 40-100 °C have shown52 ... 

The reaction of PAN with hydrogen sulfide was for the first time achieved in DMF solution at 50-70 °C. It has been shown that under these conditions the nitrile groups are partially converted into thioamide groups and polymers corresponding to copolymers of AN with acrylthioamide are formed54 ... 

Recently Keumi et al. (1989) found that arenediazonium tetrafluoroborates readily decompose in the presence of azidotrimethylsilane in DMF solution to afford the corresponding aryl azides. 

ABA type poly(hydroxyethyl methacrylate) (HEMA) and PDMS copolymers were synthesized by the coupling reactions of preformed a,co-isocyanate terminated PDMS oligomers and amine-terminated HEMA macromonomers312). Polymerization reactions were conducted in DMF solution at 0 °C. Products were purified by precipitation in diethyl ether to remove unreacted PDMS oligomers. After dissolving in DMF/toluene mixture, copolymers were reprecipitated in methanol/water mixture to remove unreacted HEMA oligomers. Microphase separated structures were observed under transmission electron microscope, using osmium tetroxide stained thin copolymer films. 

Kinetic measurements were performed on a Hitachi 150-20 UV/VIS spectrophotometer. Dehydrobrominations were studied in DMF solution using cyclohexyl amine (CHA) as the base. Applied CHA concentrations were 2, 2.5, 3, 3.5, 4 and 5 10 3 mole.dm-3, initial concentration of 1 was 5 10 5 mole.dm-3 in every case (pseudo-first-order conditions). Ionic strength was adjusted to lO l mole.dm 3 with potassium nitrate. Kinetic curves / D(t) / were recorded at fix wavelength, X = 290 ran and the temperature was maintained at 30, 35.5, 40°C. Stock solutions were made daily for la and freshly for every measurement of Ih. The reaction was started by injection of solution of 1 to the thermostated solution of CHA. 

The SWNT/MEHPPV composites were prepared by the following procedure. The shortened SWNTs were added to a DMF solution of MEHPPV. The suspension was then sonicated with a bath-type sonicator. Centrifugation (6000 rpm) of the suspension for 15 min gave a DMF solution of the SWNT/MEHPPV composite. 

The formation of SWNT/MEHPPV composites was confirmed by absorption and fluorescence spectra. The DMF solution of SWNT/MEHPPV composites or the aqueous solution of the shortened SWNTs was then dropped onto a mica or glass plate. The magnetic processing of the composites or the SWNTs was carried out by using a superconducting magnet (8T) in the horizontal direction, as described below. 

The use of y-ray induced radical pol5unerization proved to be a successful alternative for the radical co-polymer-ization of metal complexes with ligands containing acrylic C—C double bonds [100-102,129,130]. In particular, the palladium(II) complex cw-[PdCl2(ICPA)2] (1, Scheme 4) was co-polymerized in DMF solution with DMA and MBAA (cross-linker, 4% mol), with no degradation of the metal center [100,101]. 

HS-GC methods have equally been used for chromatographic analysis of residual volatile substances in PS [219]. In particular, various methods have been described for the determination of styrene monomer in PS by solution headspace analysis [204,220]. Residual styrene monomer in PS granules can be determined in about 100 min in DMF solution using n-butylbenzene as an internal standard for this monomer solid headspace sampling is considerably less suitable as over 20 h are required to reach equilibrium [204]. Shanks [221] has determined residual styrene and butadiene in polymers with an analytical sensitivity of 0.05 to 5 ppm by SHS analysis of polymer solutions. The method development for determination of residual styrene monomer in PS samples and of residual solvent (toluene) in a printed laminated plastic film by HS-GC was illustrated [207], Less volatile monomers such as styrene (b.p. 145 °C) and 2-ethylhexyl acrylate (b.p. 214 °C) may not be determined using headspace techniques with the same sensitivities realised for more volatile monomers. Steichen [216] has reported a 600-fold increase in headspace sensitivity for the analysis of residual 2-ethylhexyl acrylate by adding water to the solution in dimethylacetamide. 

A comprehensive series of mono- and dinuclear iodoplatinum(II) complexes [Ptl(dien)]+ and [ PtI(dien) 2(/r-CH2) ] (42) (dien = parent or substituted diethylenetriamine n = 2-9), respectively, have been synthesized as potential probes of nucleic acid structure.158 Both chiral and achiral species were prepared. In general, the complexes are synthesized by the reaction of trans-[PtI2(DMSO)2] with the dien ligand in DMF solution. 

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