Phenylazobenzoic Acid

Fifty-four grams (0.39 mole) of -aminobenzoic acid is dissolved in 390 ml. of warm glacial acetic acid in a 1-1. Erlenmeyer flask. The solution is cooled to room temperature, 42 g. (0.39 mole) of nitrosobenzene (p. 80) is added, and the mixture is shaken until the nitrosobenzene dissolves. The flask is stop- 

The / -phenylazobenzoic acid is collected on a Buchner funnel (Note 1) and washed with acetic acid and with water. The yield of air-dried acid melting at 245-247° cor. is 62 g. (70%). By recrystallization from 95% alcohol (60 ml. per g.) the acid is obtained as orange-gold plates which melt at 248.5 249.5° cor. the yield is 54 g. (61%). 

The solution is not cooled below room temperature before filtering cooling below 20° brings down impurities. 

The method employed here is essentially the one described by Angeli and Valori.1 

Submitted by George H. Coleman, Gust Nichols, Chester M. McCloskky, and Harry D. Anspon. 

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Fifty grams (0.22 mole) of recrystallized />-phenylazobenzoic acid (p. 86) (Note 1) and 50 g. (0.47 mole) of anhydrous sodium carbonate (Note 2) are placed in a 1-1. flask and thoroughly mixed by shaking. To this mixture is added 250 ml. (3.5 moles) of... 

Phenylazodiphenylamine A420-R Phenylazobenzoic Acid. See Azobenzene-carboxylic Acid A650-R Phenylazoxybenzoic Acid. See Azoxybenzene-carboxylic Acid A668-L N,N-o-Phenyleneguanidine. See 2-Amino-benzimidazole A187-L Phenylethanolamine. See under Anilinoethanol A424-L... 

A mixture of 27.2 g of 3,5-dihydroxy-4-phenylazobenzoic acid methyl ester, 150 ml of methanol and 64 g of dimethyl sulfate was treated during 45 minutes with a solution of 23 g of sodium hydroxide in 50 ml of water while stirring. Care was taken that the temperature did not exceed 55°C by means of a cooling bath. The mixture was stirred at room temperature for a further 1 hour, cooled with ice water, filtered off under vacuum and recrystallized from 400 ml of ethanol. Red crystals of 3,5-dimethoxy-4-phenylazobenzoic acid methyl ester were obtained melting point 130°-132°C. 

N-Phenylanthranilic acid, 22, 5 Phenyl azide, 22, 96 -Phenylazobenzoic acid, 25, 86 -Phenylazobenzoyl chloride, 25, 87 Phenylbenzoyldiazomethane, 20, 48 a-Phenyl-0-benzoylpropionitrile, 27, 33 Phenyl cinnamate, 20, 77... 

Another fascinating area of applied optics research involving LB films is photo-chromism, the ability of a material to change its absorption spectrum reversibly in response to incident optical illumination.There are many examples of photochromic organic materials some of which concern LB film assemblies. Yabe et al. have studied a photochromic system in which a phenylazobenzoic acid is housed within a... 

Renner, C., Behrendt, R., Sporlein, S., Wachtveitl, J., and Moroder, L., Photomodulation of conformational states. I. Mono- and bicycHc peptides with (4-amino)phenylazobenzoic acid as backbone constituent. Biopolymers, 54, 7, 489, 2000. 

In other experiments, poly(Lysine) was treated with p-phenylazobenzoic-N- hydroxy-succinimide ester (active esters method) in DMF/water solvent mixture. The reaction seems to be a suitable method to modify poly(Lysine) with organic reagents, and may be carried out both in organic and in aqueous solvents at acidic pH (Scheme 9) Finally, in one experiment, poly(Lysine) was acylated with p-phenylazobenzoyl chloride in DMF/water solvent mixture in the presence of excess MgO. 

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