Diphenylamine, condensation with

A halogen atom directly attached to a benzene ring is usually unreactive, unless it is activated by the nature and position of certain other substituent groups. It has been show n by Ullmann, however, that halogen atoms normally of low reactivity will condense with aromatic amines in the presence of an alkali carbonate (to absorb the hydrogen halide formed) and a trace of copper powder or oxide to act as a catalyst. This reaction, known as the Ullmant Condensation, is frequently used to prepare substituted diphenylamines it is exemplified... 

Other Uses. More than 70 thousand metric tons of acetone is used in smaU volume appHcations some of which are to make functional compounds such as antioxidants, herbicides, higher ketones, condensates with formaldehyde or diphenylamine, and vitamin intermediates. 

Heating the sugar with strong acid yields furfural derivatives. Aldohexoses can eliminate water and formaldehyde under these conditions yielding furfural. This adehyde reacts with amines according to I to yield colored Schiff s bases. Ketohex-oses condense with diphenylamine in acid medium with simultaneous oxidation according to II to yield the condensation product shown. 

Diphenylamine—Phosphoric Acid Reagent), these condense with aniline to Schiff s... 

In the presence of anions which are precipitated by calcium chloride solution, proceed as follows. Precipitate the acetic acid test solution with calcium chloride solution, and collect the precipitate on a filter or in a centrifuge tube. Remove the water from the precipitate either by drying or by washing with alcohol and ether. Mix a small amount of the precipitate with diphenylamine in a dry micro test-tube, add a little concentrated phosphoric acid, and heat gently over a free flame. Calcium phosphate and free oxalic acid are formed, and the latter condenses with the diphenylamine to aniline blue and colours the hot phosphoric acid blue. The colour disappears on cooling. Dissolve the melt in alcohol, when a blue colouration appears. Pour the alcoholic solution into water thus precipitating the excess of diphenylamine, which is coloured light blue by the adsorption of the dyestuff. The dye may be extracted from aqueous solution by ether. 

For distilling liquids, coil condensers are used, or, in some cases, straight-tube condensers with multiple tubes (20 to 30). These condensers can also be heated, so that diphenylamine or other easily melted products can be handled in them in the event that it is not feasible to use steam distillation (see pages 140-142). 

Aromatic amine antioxidants were prepared by condensation of aniline, aralkylated diphenylamine or 2,2,4-trimethyl-l,2-dihydroquinoline with formaldehyde [165]. The latter was also used for the synthesis of other stabilizers a LS was formed via condensation with 2,4-dihydroxybenzophenone [166], a MD 131 with 2-hydroxy 4-methoxyacetophenone [167], another MD was formed with 8-hydroxyquinoline [168] and a BIO-S 132 with 4-aminosalicylic acid [169]. 

The synthesis of SFs-substituted phenothiazine was disclosed in a patent from Smith, Kline French Laboratories (63USP3107242). 3-SFs-Acetanilide (120), prepared by acetylation of d-SFs-aniline (39) with acetic anhydride, was first condensed with bromobenzene under basic conditions, in the presence of Cul and copper-bronze powder, and after add hydrolysis provided 3-SFs-diphenylamine (121). This product was then fused with sulfur in the presence of a catalytic amount of iodine to give 2-SFs-phenothiazine (122) in unreported yield (Scheme 34). 

Also, acetone is reacted with diphenylamine to make the antioxidant known as an acetone diphenylamine condensation product. 

Diphenylamine reacts with acetone to produce acetone diphenylamine condensation product antioxidant for rubber. 

For the synthesis of pyrayafoline (41), l-bromo-3-methoxy-4-methylbenzene (67) was condensed with 2,3 [2, 2 dimethyl-A -pyrano-]-aniline acetate (119) to furnish the diphenylamine derivative... 

For synthesis of pyrayaquinone A and pyrayaquinone B 42) 7-Amino-2,2-dimethyl-chromene (122) prepared from m-hydroxyacet-amide (123) gave on condensation with 2-methylbe(nzoquinone (124) diphenylamine (125) which on cyclisation with pall ium acetate afforded pyrayaquinone A (25). Similarly 5-amino-2,2-dimethylchromene (126) on condensation with 2-methylbenzoquinone (124) afforded the diphenylamine derivative (127) which on cyclisation by the above method furnished pyrayaquinone B (26). 

In the synthesis of commercial sulfur-heterocycles two interesting reactions are used (i) diphenylamines may be connected by a sulfur bridge in the orfho-positions (ii) the amino grouping of sulfonamides undergoes condensation reactions with neighboring imino- and amide groups. 

Qualitative Analysis. Several quaUtative analyses can be employed. For example, in the oxamide method (59), oxaUc acid is first heated at approximately 200°C with concentrated aqueous ammonia in a sealed tube. When thiobarbituric acid is added and heated to 140°C, a condensed compound of red color forms. The analysis limit is 1.6 pg. In the diphenylamine blue method (59,60), oxaUc acid is heated with diphenylamine to form a blue color, aniline blue. The analysis limit is 5 pg. 

An acridine with a radically different substitution pattern, interestingly, still exhibits antimalarial activity. Condensation of acetone with diphenylamine in the presence of strong acid affords the partly reduced acridine, 20. Alkylation with 3-chloro-dimethylaminopropane (via the sodium salt of 20) affords dimethacrine (21). ... 

In a 2-1. three-neck, round-bottom flask, fitted with a very efficient mechanical stirrer, a 100-cc. separatory funnel and a large air-cooled reflux condenser (Note 1), the upper part of which is bent downwards and attached to a vertical water condenser, are placed t. jS g. (r.04 moles) of ground diphenylamine (Note 2), 204 g. (1 mole) of iodobenzene, 11. of nitrobenzene (Note 3), 138 g. (1 mole) of finely powdered anhydrous potassium carbonate and 5 g. of copper powder (Note 4). 

Dinitro-diphenylamin)-<3 azo-3> (2 .4 -dinitro-diphenylamin) in Ger], [(02N)2CgH3-NH.CgH4.N. ]2 mw 544.43, N 20.58% golden-yel ndls(from pyridine), mp 285° sol in hot pyridine and in benzoic acid ethylester insol in other solvs was prepd by the condensation of 3"amino -3 -(2,4-dinitroanilino)-azobenzene with 4-chloro -1,3-dinxtrobenzene... 

As in the case of the metal-free direct dyes, a large diversity of structures is encountered here, too, there are direct dyes with pyrazolones, substituted 4,4 -diphenylamines, or the 1,3,5-triazine ring, urea and stilbene derivatives, and condensation dyes. 

Aromatic amines, such as phenyl- -naphthylamine or condensation products of diphenylamine with acetone condensates, are excellent antioxidants and antiozonants but cause color development. From the sterically hindered phenols, monocyclic phenols, such as 2,6-di-teit-butyl-p-cresol, are less effective antioxidants but remain white and nontoxic during aging. They are, however, volatile and provide poor protection at elevated processing temperatures. Polycyclic phenols, such as 2,2 -methylene-bis (4-methyl-6-teit-butylphenol), are relatively nonvolatile, but become discolored by oxidation to a conjugated system. O Shea... 

Phenotellurazine 26.5 g (0.16 mol) of diphenylamine, 50 g (0.16 mol) of mercury(ll) acetate, and 500 ml of methanol are placed in a 1-/ round-bottom flask fitted with a magnetic stirrer and a reflux condenser. The mixture is stirred and heated under gentle reflux for 12 h, cooled to 20c, and a solution of 14.0 g of lithium chloride in 50 ml of methanol is added. The resultant mixture is stirred at 20° for 12 h, and the colourless solid is filtered and dried in a dessicator yield of dry 2-chloromercuriodiphenylamine 56 g (80%). 

Another way to obtain suitably substituted diphenylamines is the condensation of o-aminophenols with activated 1,2-dihalobenzenes.24 The reaction was performed in nonalkaline medium. It is interesting... 

Fig. 24. Apparatus for large-scale distillation with superheated steam (for o-naphthylamine, diphenylamine, etc.) (1) inlet for superheated steam (2) distillation vessel with slow stirrer (3) coil condenser.

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