A./V-Dimethylacetamide

The step 1 product (25.6 mmol) dissolved in 10 ml A,/V-dimethylacetamide was treated with morpholine (12.3 mmol) at 100°C and then stirred at 140°C for 15 hours and... 

A,/V-Dimethylacetamide [127-19-5] M 87.1, h 58.0-58.5 /11.4mm, d 0.940, n 1.437. Shaken with BaO for several days, refluxed with BaO for Ih, then fractionally distd under reduced pressure, and stored over molecular sieves. 

A. E. Wick, D. Felix, K. Steen, and A. Eschenmoser, Claisen sche umlagerungen bei allyl- und benzylalkoholen mit hilfe von acetalen des A((V-dimethylacetamids, Helv. Chim. Acta 47 2425 (1964). 

Acetylation has also been carried out with A/,/V-dimethylacetamide/ phosphoryl chloride, and is —5 x 103 times slower than formylation with DMF/phosphoryl chloride [74JCS(P2)1610]. This finding is consistent with greater delocalization of the charge in the electrophile for the acetylation compared to the formylation. 

Several thiopropargylimines 32 underwent ring-closure to the pyrroles 33 upon treatment with Cul in hot A V-dimethylacetamide (DMA). This process involves a propargyl-allenyl isomerization followed by a 1,2-migration of the thio-group in the intermediate allenes <03AG(E)98>. 

As there are difficulties in exchanging the 2-ethoxy group for an amino substituent, the condensation of a 5-aroylpyridazin-4-amine with A,)V-dimethylacetamide dimethyl acetal provides a better route to 4-aryl-iV,Ar-dimethylpyrido[2,3-d]pyridazin-2-amine 5a.66 If, in the reaction with 5-benzoylpyridazin-4-amine, A, A dimethylacetamide dimethyl acetal is used together with cyclic secondary amines, the corresponding 4-phcnylpyrido[2.3-r/]pyridazin-2-amines 5b g are obtained.67... 

NaOMe (0.162 g, 3 mmol) was added to a solution of bis(4-methylbenzoyl)methane (0.504 g, 2 mmol), 4-tolylnitromethane (0.604 g, 4 mmol) and AcCI (0.322 g, 4.1 mmol) in A V-dimethylacetamide (3 mL). The mixture was stirred at 80-85 °C. overnight and then neutralized with 1 M HC1. The resulting mixture was extracted with benzene and the dried extract was chromatographed (silica gel, benzene/EtOAc 20 1) to give the product yield 0.157 g (41%) colorless needles mp 238-241 C (EtOAc/hexane). 

Primary and secondary trifluoromethylsulfones (triflones) such as 12 are efficiently obtained from readily available sodium trifluoromethanesulfinate (10) and alkyl bromides (e.g., 11) in A%V-dimethylacetamide (DMAC).12 Simple primary alkyl bromides may also be employed. 

Hydrophilic additives, such as LiCl and polyvinylpyrrolidone (PVP), are used to modify the morphology of PVDF membranes by acting on the thermodynamic and kinetic mechanisms occurring during the phase inversion process. These additives are soluble both in A/,V-dimethylacetamide (DMA) and HjO, and are leached out of the cast solution exchanging with the coagulation bath. 

A,A-dimethylacetamide (DMAC) impurities A,./V-dimethylacetonitrile, DMF, DMAC, A-methylacetamide, and acetamide... 

Several optimization studies have been carried out under these phosphine-free conditions. The reaction of bromobenzene and styrene was studied using Pd(OAc)2 as the catalyst, and potassium phosphate and (V,(V-dimethylacetamide (DMA) were found to be the best base and solvent. Under these conditions, the Pd content can be reduced to as low as 0.025 mol %.142 The reaction of substituted bromobenzenes with methyl a-acetamidoacrylate has also been studied carefully, since the products are potential precursors of modified amino acids. Good results were obtained using either N, (V-diisopropylethylamine or NaOAc as the base. 

The fluoran 89 reacts with phenols in /V./V-dimethylacetamide in the presence of potassium carbonate to give 2 -anilino-6 -( /V-ethyl-/V-[3-(4-methylthiophenoxy)propyl]amino -3 -methylfluoran (90a),71 2 -anilino-6 - A-ethyl-fV-[3-(3,5-difluorophenoxy)propyl]amino -3 -methylfluoran (90b),71 2 -anilino-6 -(7V-ethyl-7V-[3-(3-methylphenoxy)propyl]amino -3 -methylfluoran (90c),71 etc. in excellent yield. 

A 500-ml reaction flask was charged with the step 1 product (43.1 mmol), the poly condensate of 4,4 -dichlorobenzophenone-2,2-bis(4-hydroxyphenyl)-1,1,1,3,3,3-hexa-fluoropropane (Mn 11,200 Da 1.80 mmol), bis(triphenylphosphine) nickel dichloride (1.35 mmol), sodium iodide (5.85 mmol), triphenylphosphine (18 mmol), and zinc (108 mmol). The mixture was dried under vacuum and then treated with 87 ml of N,N-dimethylacetamide and kept in the temperature range of 70-90°C. After 3 hours the mixture was diluted with 200 ml of V,V-dimethylacetamide and insoluble components removed by filtration. The filtrate was then added to 1.5 liters of methanol containing 10 vol% concentrated hydrochloric acid to precipitate the polymer. After collecting, the precipitate was dried to obtain 28.5 g of product having polyhydroxyl groups. 

The step 2 product (12.41 mmol) dissolved in 10 ml (V -dimethylacetamide was treated with a mixture of hydroxylammonium chloride (2.90 mmol) and sodium acetate (2.90 mmol) dissolved in 5 ml water and then stirred at 100°C for 4 hours. The mixture was treated with water and a brownish yellow solid isolated. This material was washed with water, dissolved in CH2C12, and dried using MgS04. It was concentrated, repurified by precipitation in CH2Cl2/hexane solution, and 0.81 g product isolated. 

The oxygen behaves as a Lewis base and the hydrogen behaves as a Lewis acid. /V,/V-dimethylacetamide has no acidic hydrogen, and hydrogen bonding cannot occur. 

Fig. 5. Changes in ( ) content of the trans azobenzene residues in polyamide (6) backbone and (O) viscosity of the polyamide in V,V-dimethylacetamide on alternate irradiation with ultraviolet (410 nm > A > 350 nm) and visible (A > 470 nm) light at 20 °C [14], Polymer concentration was 0.9 g/dl...

A solution of equivalent amounts of 2-benzoyl-3-phenyl-2//-azirine and 4-methylbenzonitrile oxide in V.V-dimethylacetamide was treated with an equivalent of 1 M methanolic NaOMc and the reaction mixture was worked up as described for procedure A to yield the product (13%) mp 188- 190 aC. 

---