7V,A/-Dimethylformamide

Ref. 616) was prepared from the per-ALtosyl-3 -0-sulfonylkanamycin B derivative 686, after conversion into the 2, 3 -ALtosylepimine 687 (with NaOMe in MeOH), by treatment with KHF2 in 7V,A -dimethylformamide (DMF 150°, 2 h, giving the 3 -deoxy-3 -fluoro derivative 688 in 60% yield). 

Many chlorinations of pyrazines have been achieved with sulfuryl chloride. A series of monoalkylpyrazines has been chlorinated specifically in the 3-position with sulfuryl chloride in the presence of 7V,A -dimethylformamide for example, 2 -butylpyrazine in MjV-dimethylformamide with sulfuryl chloride at 45° gave 2iS-butyl-3-chloropyrazine. The nucleus of 2,6-dialkylpyrazines was also readily chlorinated (687, 693). 2,6-Dimethylpyrazine and sulfuryl chloride in A. A -dimethyl-formamide gave 2-chloro-3,5-dimethylpyrazine (687, 844), and 3-methoxy-2,5-dimethylpyrazine gave 2-chloro-5-methoxy-3,6-dimethylpyrazine (844). 

Iridium trichloride trihydrate (3.52 g, 10 mmol) and triphenylphosphine (13.1 g, 50 mmol) is added to 7V,A -dimethylformamide (150 ml). The mixture is stirred and refluxed for 12 h. The red-brown solution is filtered while hot, and immediately warm methanol (300 ml) is added to the filtered solution. After the mixture is cooled in an ice bath, the yellow crystals are filtered and washed with ice-cold methanol. The crystals are dried under vacuum. Yield 6.8-7.0 g (87-90 %). The crystals are air-stable, but take up oxygen in solution. Soluble in benzene and chloroform but insoluble in alcohols. 

The simplest reactions involve only mass transfer of a reactant to the electrode, heterogeneous electron transfer involving nonadsorbed species, and mass transfer of the product to the bulk solution. A representative reaction of this sort is the reduction of the aromatic hydrocarbon 9,10-diphenylanthracene (DPA) to the radical anion (DPAt) in an aprotic solvent (e.g., 7V,A-dimethylformamide). More complex reaction sequences involving a series of electron transfers and protonations, branching mechanisms, parallel paths, or modifications of the electrode surface are quite common. When a steady-state current is obtained, the rates of all reaction steps in a series are the same. The magnitude of this current is often limited by the inherent sluggishness of one or more reactions called ratedetermining steps. The more facile reactions are held back from their maximum rates by... 

Liquid-liquid equilibrium data of poly(ethersulfone) in 7V,A -dimethylformamide and water... 

Halocyclization of the amide 5 (R1 = C6H5 R2 = H R3 = CH3), derived from (S)-proline and ( )-2-methyl-3-phenyI-2-propenoic acid, can be performed by stirring a mixture of the potassium salt of 5 and 2 equivalents of TV-bromosuccinimide in dimethylformamide for 48 hours. This results in a 99 1 (transjeis) mixture of lactones 6 in 91 % yield1. Debromination of the crude lactone, followed by acidic hydrolysis, gives ( + )-(/ )-2-hydroxy-2-methyl-3-phenylpropanoic acid fmp 115-117 °C [a]D + 16.7 (c = 5.71, dioxane)3] in 36% overall yield. Other bromolactones 6 can be similarly prepared from the corresponding (S)-7V-(a,/l-unsaturated acyl)prolines 5. 

The reduction of cycloheptatriene was studied in aprotic solvents at a platinum electrode. A reversible wave at —2.5 V for the production of the radical anion was observed in ammonia containing 0.1 M KI. Quasi-reversible or irreversible reduction was observed in acetonitrile and in 7V,iV-dimethylformamide (equation 34) . ... 

V,iV-Dimethylformamide dimethyl acetal can be used to obtain iV-benzyldihydroindo-le-7(6/f)ones in good yield by reaction with a -methyl derivative of a cyclic ketoenamine (equation 231). Apparently no other substitution in 1,2,3-position of indole is available by this method. ... 

Dimethyl sulfoxide (DMSO) and 7V,N-dimethylformamide (DMF) are widely used as reaction media and as solvents for solid substances. They are the precursors of many sulfoxides (250) and amides (251) which are reported to form a variety of complexes with... 

DMSO and A/,A/-dimethylformamide (DMF) are particularly efiective in enhancing the reactivity of enolate ions, as Table 1.2 shows. Both of these compounds belong to the polar aprotic class of solvents. Other members of this class that are used as solvents in reactions between carbanions and alkyl halides include 7V-methylpyrrolidone (NMP) and hexamethylphosphoric triamide (HMPA). Polar aprotic solvents, as their name implies, are materials which have high dielectric constants but which lack hydroxyl groups or other... 

Spray solution Ilb Dissolve 1 g 7V-(l-naphthyl)ethylenediamine dihydrochloride in 50 ml dimethylformamide and 50 ml hydrochloric acid (< Hci = 4 mol/1) with warming. If the cooled solution is not clear it should be filtered. A pale violet coloration does not interfere with the reaction [4]. 

Trimethylsilyl halides can also be used for analogous reactions with arenediazo-nium tetrafluoroborates, as shown by Keumi et al. (1989). These authors treated 2-fluorenediazonium tetrafluoroborate in A/,Af-dimethylformamide or -acetamide with trimethylsilylchloride, -bromide, or -iodide in the presence of an excess of N-chlorosuccinimide, Af-bromosuccinimide, or methyl iodide, respectively, at 60 °C (Cl, Br) or at room temperature (I). The yields of the 2-halofluorenes were good in addition fluorene, the product of hydro-de-diazoniation, was obtained, if the reaction was run in tetrahydrofuran/Af,7V-dimethylformamide mixtures. The mechanism of these reactions, as well as that of the corresponding azido-de-diazoniation, is uncertain (see also Secs. 10.2 and 10.7). 

Other A/7V-dialkylformamides including commercially available TV-methylformanilide, N-formylmorpholine, /V-formylpipcridinc, A/iV-diethylformamidc and A, jV-dimethylformamide (DMF) can be employed with essentially the same procedure. With /V,/V-dimethylformamide, care has to be exercised because of the volatility of the product, which can be purified by distillation or chromatography of its hydrochloride salt. 

Dimethylethyl) -3- (methylthio) -1,2,4 -triazin-5 - (4 H) -one, see Metribuzin 7V,7V-Dimethylformamide, see Dimethylamine Dimethyl hydrogen phosphate, see Dichlorvos TV.O-Dimethylhydroxylamine, see Linuron 0,0-Dimethyl 5- (TV-hydroxymethylcarbamoyhnethyl) phosphorothioate, see Dimethoate 0,0-Dimethyl 5- (TV-hydroxymethylcarbamoyhnethyl) phosphorothiolate), see Dimethoate 0,0-Dimethyl 5- (A-methylcarbamoylmethyl) phosphorothiolate, see Dimethoate O, O-Dimethyl-0- (4- (methylthio) -m-tolyl) phosphate. 

Since anodically prepared a-formyloxy-lV,7V-dimethylformamide has successfully been used as an electrophilic reagent, and it has been found that the a-methoxylation of the carbamates of a variety of higher aliphatic amines and alicyclic amines can be readily performed, extensive studies have been carried out to utilize the anodically synthesized a-methoxy- or a-acyloxy-amides and -carbamates as electrophiles in organic synthesis. One example is shown in equation (Sl). ... 

Diamino-3-carboxy-5-chloropyrazine A, 7V-diphenylcarbamic anhydride (19), an active ester, has been prepared by addition of diphenylcarbamoyl chloride to 2,6-diamino-3-carboxy-5-chloropyrazine and triethylamine in dimethylformamide, (and other similar compounds were also prepared) (1330, 1344, 1345). This compound was better prepared from 2,6-diamino-3-carboxy-5-chloropyrazine and... 

Reduction of V, R = Me, in dimethylformamide at mercury leads to conversion of the ketone function to secondary alcohol with essentially no cyclization process observed. However, in the presence of a mediator the course of reaction changes. Addition of N,N-dimethylpyrrolidinium fluoroborate causes formation of the cyclized tertiary alcohol. The pyrrolidinium salt is reduced at —2.7V (vs. SCE) at mercury to yield a complex DMP(Hg5) which is thought to act as a single-electron-transfer mediator [42]. Cyclization also occurs in dimethylformamide at a mercury cathode using a homogeneous redox catalyst such as phenanthrene or 2-methoxybiphenol with a redox potential in the range —2.4 to —2.7 (vs. SCE) [43]. Because during these reactions one electron is delivered to the carbonyl compound in solution by the reduced mediator, cyclization of the reduced carbonyl compound can occur before a second electron donor is encountered. 

V,7V,7V,7V -tetrakis(2-hydroxybenzyl)ethylenediamine forms a non-oxovanadium derivative.640 The electrochemical properties of this derivative have been determined in dimethylformamide and two well-defined reversible one-electron-transfer events were detected at +0.16V for E11/2 and at -0.84 V for E21/2 (vs. Fc+/Fc) these potentials correspond to the V5+/4+ and V4+/3+ redox couples, respectively.640... 

Ai -Cyclopropoxymethyl-7V-methyl amides of formic acid and acetic acid have been obtained in moderate yield by treating the corresponding trimethylsiloxycyclopropanes with mixtures of ethyl azidoformate and dimethylformamide (e.g. formation of 6) and Af,Af-dimethylacet-amide, respectively, at 120 C. Presumably, the reaction involves a singlet nitrene species. 

Otto reported (71AP505) (Scheme 72) that pyrazol-3-one 62 reacts at ambient temperature with thiophenol in dimethylsulfoxide to afford 4-phenylthiopyrazol-3-one 227 in 81% yield. It is interesting that sulfonium ylid 226 was the proposed intermediate since it could be formed by reacting pyrazol-3-one 62 with acetic anhydride in dimethylsulfoxide and could then be converted into product 226 by reacting with thiophenol in 7V,7V-dimethylformamide and a catalytic amount of 4-toluenesulfonic acid. 

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