Aniline Preparation

Dissolve 47 g. (0-5 mole) of aniline in a mixture of concentrated hydrochloric acid and water (100 c.c. of each) and diazotise the well-cooled solution, in the manner repeatedly described, with a solution of 38 g. of sodium nitrite in 100 c.c. of water. Before diazotising the aniline, prepare as concentrated a solution as possible in water of 158 g. (1-25 mole) of neutral anhydrous sodium sulphite or of 315 g. of the hydrated (7 H20) salt. The sulphite content of this solution is equivalent to the amount of hydrochloric acid taken, and represents a 25 per cent excess in respect of the aniline. 

The gas mixture is passed at a velocity of i litre a minute through two bubblers containing 25 ml. of an aqueous solution of aniline prepared as described on p. 84. 

The time required for sulfonation may be reduced to one hour if 25 ml of fuming sulfuric acid (containing 15-20 per cent sulfur trioxide) is added cautiously to the mixture of acid and aniline prepared as directed above. The reaction mixture is heated for one hour at 180-190° and tested for completion of the sulfonation. When the reaction is complete, cool to room temperature, then pour cautiously, with vigorous stirring, into 300 ml of cold water. Filter the crystals of the crude acid, and wash several times with cold water. Purify the crude acid by dissolving in 200 ml of warm water and adding dilute sodium hydroxide until solution is complete. Add a gram or two of charcoal and a pinch of Filter-cel. Stir and heat to 80-90°, and filter with suction. Acidify the solution with dilute hydrochloric acid, and cool to 10-15°. Filter the crys-... 

The chemistry of mass-selected ionized halobenzenes toward ammonia in a quadrupole collision cell pointed out that the CA spectra of the m/z 94 ions, i.e. protonated aniline, prepared in each of these conditions are qualitatively similar, since all the fragmentations are common. The major observed differences concern the relative intensities of the peaks associated with charge stripping and ammonia loss. In this context, substituted benzenes protonated on a ring carbon atom are more prone to undergo double ionization than substituted benzenes protonated on a substituent. 

With the aniline prepared above, the following experiments are made ... 

ULLMAN METHOXYLATION IN THE PRESENCE OF A 2,5-DIMETHYLPYRROLE- 63 BLOCKED ANILINE PREPARATION OF 2-FLUORO-4-METHOXYANILINE. 

In a number of multicomponent condensation reactions, TMSCl has also been utilized to improve the yield or efficacy of the desired product, or is directly incorporated into the final molecules. Examples include the synthesis of Al-aryl-3-arylamino acids from a three-coir onent reaction of phenols, glyoxylates, and anilines, preparation of 2,4,5-trisubstituted oxazoles, or 4-cyanooxazoles, and the three-component BigmeUi reaction... 

XXXI. EXPERIMENTAL DETAILS OF POLY(ANILINE) PREPARATIONS... 

Chang K.-C., Lai M.-C., Peng C.-W, Chen Y.-T., Yeh J.-M. et al. (2006), Comparative studies on the corrosion protection effect of DBSA-doped poly aniline prepared from in situ emulsion polymerization in the presence of hy drophihe Na -MMT and organophUic organo-MMT clay platelets , Eleetroehim. Aeta, 51,5645-53. 

Hino, T, Namiki, T, Kuramoto, N. Synthesis and characterization of novel conducting composites of poly aniline prepared in the presence of sodium dodecylsulfonate and several water soluble polymers. Synthetic Metals (2006), 156,1327. 

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