Dimethylaniline sulfonic acid

The best source of information on preparative aspects of coupling reactions is still the book of Fierz and Blangey (1952). Four examples of coupling reactions can be found in Organic Syntheses (Conant et al., 1941, and Fieser, 1943 Azo coupling with 1- and 2-naphthol Hartwell and Fieser, 1943 8-Hydroxy-l-naphthylamine-2,4-di-sulfonic acid Clarke and Kirner, 1941 A/,7V-Dimethylaniline). 

Table I shows the effect of various systems such as micelles, swollen micelles (achieved by adding hexanol to CTAB), microemulsion systems, vesicles formed from a double-chain CTAB surfactant, and reversed micelles with water cores formed with benzyl dimethylcetylammonium bromide in benzene. Hie active chromophore exists either as pyrene, pyrene sulfonic acid or pyrene tetrasulfonlc acid. Essentially the concept here is that the polar derivatives of pyrene will always locate pyrene at the surface of the micelle as these anionic species of pyrene complex with the positively charged surface. Dimethylaniline is used as an electron donor in each case, it can be seen that for pyrene, a continual decrease in the yield of the pyrene anion (ion yield of unity in the micelle) is observed on going from micelle to swollen micelle, to microemulsion, and no yield of ions is observed in a reversed micelle system. With pyrene tetrasulfonic acid the yield of ions over the different systems is fairly constant, even across to the reverse micellar system. However, the lifetime of the ions is extremely short in the reversed micellar system. An explanation for such behavior can be given as follows as we transverse across the...

Polyaniline and its substituted derivatives, such as poly(o-toluidine), poly(o-anisidine), poly(N-methylaniline), poly(N-ethylaniline), poly(2,3-dimethylaniline), poly(2,5-dimethylaniline) and poly (diphenylamine) have been reported [36] to show measurable responses (sensitivity 60%) for short chain alcohols (viz., methanol, ethanol and propanol) at concentrations up to 3000 ppm. The change (decrease) in resistance of the polymers on exposure to alcohol vapors has been explained based on the vapor-induced change in the crystallinity of the polymer. Polypyrrole (PPy) incorporated with dodecyl benzene sulfonic acid and ammonium persulfate has been reported to show a linear change in resistance when exposed to methanol vapor in the range 87-5000 ppm [37]. The response is rapid and reversible at room temperature. 

Ammonium acetate Aniline Benzanthrone Bromine Carmine (Coccus cacti) Carminic acid 2-Chlorophenol Crystal violet lactone Diaminodiphenic acid Di-n-amylamine Diazoaminobenzene o,a-Dichlorotoluene Dimethoxypropane 4-Dimethylaminoazobenzene-4-sulfonic acid, sodium salt p-Dimethylaminobenzaldehyde 4-Dimethylaminobenzene 6-Dimethylaminophenylazobenzothiazole N,N-Dimethylaniline Dinitrotoluene 2,4-Dinitrotoluene Direct blue 8 Direct blue 10 Direct blue 25 Direct blue 218 Direct orange 6 Direct violet 32 Disperse blue 7 Disperse red 60 Dodecene-1 N-(p-Ethoxycarbonylphenyl)-N -ethyl-N -phenylformamidine Ethylene cyanohydrin Ethylene thiourea... 

Tetryl. In the manufacture of Tetryl, it is usual not to nitrate dime thy laniline directly, but to dissolve it first in coned sulfuric acid and then to nitrate the dimethylaniline sulfate so obtained. Direct nitration of dimethylaniline proceeds so violently that it can be carried out only under specialized conditions. Many years experience of Tetryl manufacture has shown that the ratio of sulfuric acid to dimethylaniline should not be lower than 3 1, since a smaller amount of sulfuric acid may be detrimental to the nitration process. However, the ratio of sulfuric acid to dimethylaniline must not be too high, otherwise Tetryl yield is decreased. Temp must be maintained between 20-45° to avoid sulfonation of the benzene ring. Care must be exercised not to leave any unreacted dimethylaniline prior to introduction of nitric acid, because of the potential violence of the dimethyl-aniline-nitric acid reaction. Consequently, continuous methods of prepn are to be preferred as they inherently minimize accumulation of unreacted dimethylaniline... 

A very surprising sulfone formation has been investigated by Oae and coworkers . On heating p-toluenesulfinic acid with dimethylaniline in ethanol for 15 h, the reaction mixture shown in equation 100 has been obtained. Obviously, the observed products arise from an equilibrium between the sulfinic acid and its pseudo-anhydride (disulfide trioxide), which is able to attack the amine nitrogen and degrade the tertiary amine corresponding to a Polonovsky reaction . 

Dimethylaminobenzaldehyde has been made by the condensation of chloral with dimethylaniline, and subsequent hydrolysis 1 by the hydrolysis of tetramethyldiaminobenzhydrol with acetic acid 2 by the condensation of dimethylaniline, formaldehyde and m-sulfo-/>-tolyI hydroxylamine followed by hydrolysis 3 by the electrolytic reduction of a mixture of sodium nitrobenzene sulfonate, dimethylaniline and formaldehyde, and subsequent hydrolysis 4 by the reduction of a mixture of dimethylaniline, formaldehyde and sodium nitrobenzene sulfonate with iron and hydrochloric acid, followed by hydrolysis 5 by the condensation of alloxan with dimethylaniline followed by hydrolysis 6 by the condensation of dimethylaniline, formaldehyde and sodium -toluidine sulfonate in the presence of hydrochloric acid and potassium dichromate followed by hydrolysis.7 The most satisfactory method, however, is the condensation of dimethylaniline, formaldehyde and nitroso dimethylaniline, followed by hydrolysis,8 a method which was first described by E. Noelting and later perfected in detail by L. Baumann. 

Because phenolic compounds are easily sulfonated, their sulfation must be accomplished with milder sulfating agents, eg, complexes of sulfur trioxide or chlorosulfonic acid with trimethylamine, dimethylformamide, pyridine, or dimethylaniline, in anhydrous or aqueous medium below 100°C (86-89). 

Treatment of the 2-pyrrolyl allyl thioether (498) with acetic anhydride and quinoline at 170 °C (or in A jV-dimethylaniline at ca. 100 °C) results in a thio-Claisen rearrangement to give the 5-(3-allyl-2-pyrrolyl) thioacetate (499), whilst peracid oxidation of (498) produces the non-rearranged sulfone in low yield and Raney nickel reduction of (498) yields 3-propylpyrrole (78CJC221). The polyphosphoric acid-catalyzed cyclization of (2-pyrrolylthio) acetic acid (501 R = R = H) somewhat unexpectedly yields (502) via the Spiro intermediate, instead of forming the expected oxothiolane (500), which can be obtained by a Dieckmann cyclization of ethyl (3-ethoxycarbonyl-2-pyrrolylthio) acetate (501 R = Et, R = C02Et) (B-77MI30506). 

These diazonium salts are good electrophiles for activated aromatic rings, such as amines and phenols, and this is how azo dyes are prepared. Diazotization of the salt of sulfanilic acid, which we have just made by sulfonation of aniline, gives an inner salt that combines with N,N-dimethylaniline to form the water-soluble dye, methyl orange. 

This material is of sufficient purity for most uses, including the conversion to 3,4-dimethylaniline (p. 46). It is reported that the boiling point of the product can be raised slightly (from 211-212° to 214-21S°/760 mm.) by sulfonation, recrystallization of the barium sulfonate, and regeneration of the bromo compound by acid hydrolysis. 

Although sulfonation resembles nitration and halogenation in many respects, there are certain important differences. The two most noticeable of these differences are the reversibility of sulfonation processes and the striking sensitivity of orientation to changes in the reaction temperature. Amino derivatives offer a further complication in that considerable amounts of ortho and para derivatives are often obtained. Thus at low temperatures, aniline gives a mixture of 0, m, and p-amino-benzenesulfonic acid,48 whereas dimethylaniline gives an almost equal... 

Pyridinol or 2-nitro-3-pyridinol and chlorosulfonic acid in chloroform containing dimethylaniline give the 3-pyridyl bisulfate. 2-Pyridone gives the unstable A-sulfonate and 4-pyridone gives both the A-sulfonate and the... 

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