Dimethylaniline as reagent

In a chlorination reaction using phosphoiyl chloride with dimethylaniline as acid acceptor, the reagents were added all at once. After an induction period, most of the mixture was ejected from the flask. On a smaller scale, the reaction had been uneventful. 

Although it appeared that after 1950 the Rosenmund reduction would be made obsolete by the use of hydride reagents,modifications have vastly improved on this method to provide a mild, high-yielding reaction. The addihon of a base to the system vastly aided in providing a more selective reaction that could be run under mild conditions and no longer required the use of a poisoned catalyst. Sakaurai and Tanabe reported dimethylaniline as an effective additive that allowed room temperature reactions in acetone at atmospheric pressure to provide aldehydes in 80-90 % yield. This method was used for the preparation of the bicyclo aldehyde 15 as part of the synthesis of ent-mulhfidene (Scheme... 

Organometallic reagents and alkali metal amides can react via a cyclic transition state (Section II, B, 5) beginning with electrophilic attack at the most basic ring-nitrogen. As a result, sodamide (in dimethylaniline, 145°, 2 hr) yields the 4-amino derivatives (40% yield S)) methyl- or phenyl-magnesium iodides give the 4-adduct quantitatively.s ... 

Analysis. Colorimetry with proper reagents (such as nitrophenylfluo-ronone) permits analysis down to about 100 ppb. ETAAS detects Sn down to 1 ppb, and ICPMS is effective down to 0.1 ppb, as is anodic stripping voltammetry. Spot testing involves the use of cacotheline or diazine green (a dye made by reacting diazotized safranine with dimethylaniline). Sensitivity of these is about 50 ppm. 

Coupling of compound 228 with dimethylaniline and with 2-naphthylamine afforded the azo derivatives 230 and 231. Compound 228 also coupled with active methylene reagents, such as pyrazolone 234, indan-l,3-dione 236, and cyclohexane-1,3-dione 238, to yield the corresponding arylhydrazones 235, 237, and 239, respectively <2004H(63)1143, 2004BMCL5013> (Scheme 15). 

Polynucleotides. These compounds are now generally prepared by use of a bifunctional phosphitylating agent such as o-chlorophenylphosphorodichloridite (6, 114-115) or methoxydichlorophosphine, CHjOPCl,. The intermediate nucleoside phosphites from these reagents tend to be unstable. This difficulty can be alleviated by use of I, which reacts with suitably protected nucleosides to form stable phosphoramidales 2 in good yield. These products can be activated for formation of a dinucleotide phosphite (4) by treatment with a weak acid such as N,N-dimethylaniline hydrochloride or l/Z-tetrazole (5). 

Disubstituted pyrylium salts, such as (41), are attacked at C-4 only (74JOU2015) and in the presence of perchloric acid a new pyrylium salt (42) is formed. Flavylium (43) and xanthylium (44) salts also react at the y-position, for instance, with CH-acidic reagents such as pentane-2,4-dione, malonic acid derivatives or aromatic electron-rich compounds like IV V-dimethylaniline, 1,3-dimethoxybenzene or IV-methylindole (59CB46, 74CHE1019) some examples are shown in Scheme 1. 2,4-Disubstituted pyrylium cations, e.g. (45), react at C-6 (80JOC5160). 

Cyanobenziodoxoles 36-38 are used as efficient cyanating reagents toward N,N-dialkylarylamines. In a typical example, reagent 38 reacts with N,N-dimethylanilines 39 in 1,2-dichloroethane at reflux to afford the respective N-cyanomethyl-N-methylanilines 40 in good yield (Scheme 17) [34]. 

Dimethylaniline (bp 193°) is occasionally used as a solvent for the preparation of Grignard reagents. The main impurity is monomethyl-aniline, which may be removed by treatment with a small amount of acetic anhydride. The presence of secondary amine is indicated by a temperature rise on addition of acetic anhydride, and in the absence of this impurity, the solution process is endothermic. 

In conjunction with proton sponge, the activated phosphate 256 turned out to be an effective reagent in the direct synthesis of peptides and branched amides from carboxylic acids (equation 21). In this process, diamine 1 surpassed in its efficiency for such bases as triethylamine, V,iV-dimethylaniline, 2,6-lutidine and Hiinig bases225. 

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