W-dimethylformamide, DMF

These complexes undergo two separate oxidations, both in acetonitrile (MeCN) [26, 27] and Af,W-dimethylformamide (DMF) [28] solution. As shown in Table 7-2,... 

The carboxylic acid amides most commonly studied as ligands are formamide, acetamide, and the W-substituted derivatives, particularly W,W-dimethylformamide (DMF). These compounds are often used as solvents and have high dielectric constants, particularly when they contain an N-H bond, and such uses helped to stimulate interest in the amides as ligands. There are two possible donor atoms, N or 0, but all complexes of the simple amide ligands, characterized by X-ray structure determination at least, have M-0 bonds. The amides are usually terminal ligands but can bridge between metal atoms in some instances. 

One strategy is to strongly reduce the ionic charges of the components. This was accomplished by excluding water as the solvent due to solubility problems and favoring solvents like alcohols, A,W-dimethylformamide (DMF), etc. Two examples utilizing cylindrical bmsh polymers as templates for single brush complexes have been successful so far [152, 153]. 

Wash solvents N, W-dimethylformamide (DMF) and dichloro-methane (DCM) in suitable wash botdes (fcc Note 3). 

Hurtt, M.E., Placke, M.E., Killingcr, J.M., Singer, A.W. Keimedy, G.L., Jr (1992) 13-Week inhalation toxicity study of dimethylformamide (DMF) in cynomolgus monkeys. Fundam. appl. Toxicol., 18, 596-601... 

Polyimides based on l-amino-3-phenoxy-5-(4-aminophenoxy)-benzene and snch dianhydrides as dianhydride of diphenyloxide-3,3 4,4 -tetracarboxylic acid, dianhydride A and dianhydride 6F are soluble in NMP, dimethylformamide (DMF), w-cresol, THF and chloroform. The polyimide based on benzophenone-3,3, 4,4 -tetracarboxylic acid dianhydride is partially soluble in w-cresol and NMP it is insoluble in chloroform, THF and DMF. Polypyromellitimide is insoluble in all the solvents tested. 

In a study of the dissolution of potassium bicarbonate in dimethylformamide (DMF), Compton s group used ultrasound (25 kHz, 8 W cm 2) to provide mixing [18]. The rate was monitored via the homogeneous deprotonation of 2-cyanophenol by the dissolved potassium bicarbonate (Fig. 5.15), using spectroscopic and electrochemical techniques the... 

The metal complex used was Ni(GO)4 under a carbon monoxide atmosphere in DMF at 50 °C for 3h. A suitable temperature was found to be in the range 70-90 °C and the optimum reaction time was 1-3 h. Under an inert nitrogen atmosphere the yield was reduced drastically since the CO atmosphere is essential for the reaction. The use of THF instead of dimethylformamide (DMF) led to a reduction of the yield. Similarly, when 0.1 equiv of Ni(CO)4 was used as a catalytic metal carbonylating agent, instead of 1 equiv, a low yield of the product was noted. The use of metal carbonyls such as Fe(CO)s, W(CO)s led to a negligible amount of diazetidinediones (Scheme 49). 

CHARACTERIZATION. Melting points were determined on an E. I. DuPont Series 99 Thermal Analyzer at 20°C/min. Inherent viscosities of polyamic acid solutions were obtained at a concentration of 0.5% (w/w) in DMAc at 35°C. Glass transition temperatures (T ) of the fully cured polymer films were measured by thermomechanical analysis (TMA) on a DuPont 943 Analyzer in air at 5°C/min. Films fully-cured at 300°C were tested for solubility at 3-5% (w/w) solids concentration in DMAc,N,N-dimethylformamide (DMF), and chloroform (CHCl-j). Solubilities at room temperature were noted after periods of 3 hours, 1 day and 5 days. Refractive indices of 1 mil thick films were obtained at ambient temperature by the Becke line method (11) using a polarizing microscope and standard immersion liquids obtained from R. P. Cargille Labs. 

Initially, only dipolar aprotic solvents such as W,A -dimethylformamide (DMF), N-methylpyrrolidinone (NMP), dimethyl sulfoxide (DMSO), and acetonitrile (MeCN) were common (Table 3-2). However, the presence of water has been found to accelerate certain Heck reactions [17], and consequently the development has gone to water-soluble tiiarylphosphane ligands (e.g triphenylphosphane w-trisulfonate sodium salt (TPPTS) [18a], with which many alkene arylations succeed superbly in aqueous solvent mixtures [19]. 

Shaded cells indicate compatibility of polymer with solvent or crosslinker PLA poly(lactic acid), PGA poly(glycolic acid) PLGA poly(lactic-co-glycolic acid), PCL poly(e-caprolactone), PEU poly(ester urethane), PEEUU poly(ester ether urethane), PVA poly(vinyl alcohol), PEO poly(ethylene oxide), HA hyaluronic acid, DMF W,W-dimethylformamide, A4 acetic acid, FA formic acid, DCM dichloromethane, HFIP hexafluoroisopropanol, THF tetrahydrofuran, GA glutaraldehyde, NMMO N-methyl-morpholine A -o, idc/water (NMMO/water)... 

Bu, butyl- DMAc, N,N-dimethylacetamide DMF, Ai,W-dimethylformamide DMI, Ai,A/-dimethylimidazolidinone DMSO, dimethylsulfoxide DFV, degree of polymerization as measured by viscometry NMMO, N-methylmorpholine-N-oxide TFA, trifluoroacetic acid. 

Bisbicyclic diketones (XV), (VII), and (VIII) were hydrogenated 306) under comparable conditions in a solution of dimethylformamide (DMF) at atmospheric pressure and 20-45° on Ni (W—4). Kinetic and potential curves were obtained. Some examples of the kinetic curves of hydrogenation of unsaturated ketones are shown in Fig. 25. By the method of IR spectroscopy it was established that the addition of hydrogen to the C=0 bond of (VIII) under these conditions occurs with the formation of keto alcohol (XVI), which oxidizes quite easily in the air into the keto alcohol (XVII), identified by us. 

Compound 27b was subjected to the same reaction conditions as those for the cyclization of 27a to afford 28b in a better yield (60%, Table 5, Entry 4). The reaction under solid-liquid phase transfer conditions at 100t5C using a catalytic amount of tetra-w-butylammonium chloride (/7-BU4KCI) in N, A-dimethylformamide (DMF) [83] was found to be extremely effective to afford 28b in a much improved yield (Table 5, Entry 6, 77%). 

These were prepared in a separate project (M. de L. Machado and E.W. Neuse, unpublished work) from poly-D,L-succinimide (27) by sequential treatment with R -NH2 and R -NH2 (Scheme 2). Briefly, the polyimide, dissolved in N,N-dimethylformamide (DMF), was allowed to react (5-lOh, 20-25 C) under anhydrous conditions with the first nucleophile R —NH2 in the molar ratio (x + y)/x. This was followed by treatment of the intermediate with an excess of the... 

Figure 1.10 Scanning electron micrographs of electrospun poly( -caprolactone] [PCL] fibers formed from solutions of varying PCL concentrations in methylene chloride and N,N-dimethylformamide [DMF] [50/50 w/w) solvent. (A) 20 wt% PCL, [B] 40 wt.% PCL, and [C] chart of PCL concentration [wt.%] and fiber diameter [as mean standard deviation). Reprinted from Ref. 38, 2013 by MDPI.

A solution of 4-methoxybenzaldehyde (340 mg, 2.5 mmol), 2-trifluoromethylsulfonyloxy-l-hexene (1.06 g, 4.6 mmol) and TMSCl (0.75 mL, 6.0 mmol) in A, Af-dimethylformamide (DMF) (1.5 mL) and DME (5 mL) was dropped into a suspension of Mn powder (230 mg, 4.2 mmol), CrCL (46 mg, 0.38 mmol), and NiCl (10 mg, 0.07 mmol) in dme (5 mL) at 50 °C. After stirring for 5 h at that temperature, the mixture was quenched with water (15 mL), extracted with ethyl acetate (150 mL in three portions), and the combined organic layers were washed with brine. Aqueous A7-BU4NF (75% w/w) was added, and the solution was stirred at RT until TLC showed complete desilylation of the crude product. Standard work-up... 

A convenient procedure to effect homogeneous bromination is to use elemental bromine in N,N-dimethylformamide (DMF) or N,N-dimethylacetamide (DMAC) solution. For this purpose a solution of bromine in DMF or DMAC (8% v/v) was added to the polymer dissolved in the same solvent (5% or 15% w/v), the total weights of poly(ether-urethane) and bromine being in the ratio 10 1. The solutions were stirred vigorously after mixing at 0 C for the desired time the polymer was then precipitated and washed thoroughly in distilled water before drying in vacuum at 40 C. If necessary, further purification may be carried out by additional precipitations. 

This reaction is used to make aniline derivatives. When bromobenzene (18) is heated with ethylamine (EtNH2) in aqueous solution (to about 300°C), the aromatic Sn2 reaction is slow, but the product is W-ethylaniline, 25. In general, aromatic Sn2 reactions are slow in water or alcohol solvents and much faster when tertiary amide solvents such as dimethylformamide (DMF, 155) or dime-thylacetamide (156) are used. The reaction of 18 with ethylamine, for example, gives a good yield 25 at a reaction temperature of only 160-200°C when DMF is used as the solvent. 

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