N, A-dimethylformamide

Azo-bis-isobutyronitrile average polymer chain concentration 4-aminotoluene (p-toluidine) Brunauer-Emmet-Teller cross-linking degree Cross Polarization-Magic Angle Spinning Nuclear Magnetic Spectroscopy Cyclic voltammetry N, A-dimethylformamide... 

Table 2.3 as a completely worked out example using quantitative solvent extraction, ash content determination, TGA, FTIR, XRF, GC-MS, HS-GC-MS, PyFTIR, ICP, and s-NMR. Information on the cure and antidegradant systems was obtained (assigned species/possible origin), as follows cyclohexane thiol/CBS accelerator benzothiazole/MBT, MBTS or CBS accelerators N, A-dimethylformamide/TMTD accelerator phthalim-ide/Santoguard PVI and IV-phenylbenzene amine/possi-bly a diphenyl/acetone amine antioxidant. 

N, A -dimethylformamide (DMF). This reaction proceeds by formation of the electrophilic Vilsmeier complex, followed by electrophilic substitution of the heterocycle. The formyl group is generated in the hydrolytic workup. 

Abbreviations THF, tetrahydrofuran DMF, N, A-dimethylformamide DMSO, dimethylsulf oxide HMPT, hexametapol ... 

Abbreviations DMSO, dimethylsulfoxide HMPT, hexametapol DMF, N,A -dimethylformamide DMAA, dimethylacetamide DMTAA, dimethylthioacetamide HNDMR, heteronuelear double magnetic resonance. 

As an example we describe here the synthesis of the l//-l,2,4-diazaphosphole 22 that, on account of its easy accessibility and as parent compound of the class, is of general interest. The synthesis proceeds through condensation of the cation 21. The reaction of 21 with hydrazine involves cleavage of an ammonium salt to furnish the phosphole 23.46 The cation 21 is obtained via a methanaminium chloride—generated as an intermediate from N, A-dimethylformamide and oxalyl chloride—by condensation with tris(trimethylsilyl)phosphine. 

Initial studies of solvent effects, on the reactions of triarylarsonium benzoylylides with p-nitrobenzaldehyde in N, A-dimethylformamide, dimethyl sulphoxide or methanol, indicated little solvent effect in these cases" ", but later studies of the more finely balanced reactions of semi-stabilized ylides have provided examples of strong influences due to the effect of different base and solvent when the ylide is generated in the presence of a carbonyl compound ". Thus, when benzyltriphenylarsonium bromide or p-chloroben-zyltriphenylarsonium bromide were treated with sodium hydride in benzene in the presence of a variety of p-substituted benzaldehydes the products were alkenes, but if sodium ethoxide in ethanol was used the isolated products were epoxides ". Likewise, when triphenylarsonium benzylylide was generated by phenyllithium in the presence of either benzaldehyde or acetaldehyde, the preponderant product was the epoxide whereas use of sodium amide as base provided mostly the alkene . Similar results were obtained when an allyltriphenylarsonium salt was deprotonated using different hexamethyldisilaz-... 

Methoxylation lends itself well to operation on a relatively large scale [79-83]. For instance, several A-formyl derivatives have been anodically methoxylated on a 0.5-kg scale using a capillary gap cell with a graphite anode [80,82]. An example is given in Eq. (29). Polyalkoxylation of N, A-dimethylformamide (DMF) has also been achieved [81]. 

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 100°C using a catalytic amount of tetra- -butylammonium chloride (/7-BU4NCI) 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%). 

Aprotic dipolar solvents (such as acetone and N, A-dimethylformamide). 

Tetrahydro-l//-pyrido[l,2-c]pyrimidines 189 and -1-one 190 were prepared from cyclic aminoazadienes 188 by reaction with aldehydes and triphosgene, respectively (92SL563). 4-Cyano-5,6,7,8-tetrahydro-3//-pyrido[l,2-c]pyrimidin-3-one and its 1-methyl and 5-dimethylaminomethylene derivatives were prepared in the reactions of 2-[cyano(aminocarbonyl)-methylenejpiperidine with triethyl orthoformate in acetic anhydride with N,N-dimethylacetamide diethyl acetal, or with N,A -dimethylformamide diethyl acetal (80KGS416, 80KGS1120 82KGS518). 

Fio. 1. Absorption spectrum of quinoline (3) in ethanol and di-(2-quinolyl)-methane 1, after equilibrium establishment 2, immediately after dissolution in. N,A-dimethylformamide (pure colorless form) at 20°. In, -dimethyl-formamide the rate of interconversion is so low that the spectrum of the pure colorless form can be measured. 

The combined CHCI3 extracts are stripped to dryness at room temperature (oil pump, 0.01 torr), and the residue is pumped overnight. Two consecutive recrystallizations from boiling N, A -dimethylformamide (DMF) (10 mL) gives the product as red crystals (1.17g, 70%), dec 175 C, lit. dec 180°C. ... 

To a solution of 29.0 g methyl 3-(benzyloxy)-4-methyl-5-nitrobenzoate (0.0962 mol) in 60.0 mL DMF was added 12.0 mL freshly distilled pyrrolidine (0.144 mol) and 19.0 mL N, A-dimethylformamide dimethyl acetal (of 94% purity, 0.134 mol). The dark red colored reaction mixture was heated at 110°C for 3.5 h and concentrated on a rotary evaporator. Then 350 mL CH3OH and 15 mL CH2CI2 were added to the residue, and the solution was stored at 6°C for 12 h. The garnet colored precipitate was filtered and carefully washed with cold CH3OH. Upon removal of the solvent under high vacuum, 23.24 g of a 10 1 mixture of pyrrolidino-styrene and N, A-dimethylamino-styrene was obtained, in a yield of 64%. 

Many salts, as well as most alkyl halides, possess significant solubility in dimethyl sulfoxide (DMSO) or N, A -dimethylformamide (DMF), which makes them good solvents for carrying out nucleophilic substitution reactions (Section 8.10). 

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