1885.] The Chemical Constitution of Isatin. 199 



Formula. Calculated. Found. 



C 9 108 65 '45 p. c. C 65 -26 p. c. C. 



H u 11 6 67 „ H 6-85 „ H. 



N .... 14 8-49 „ N 8 77 „ N. 



2 .... 32 19-39 „ 



165 100 -00 



Action of Bases upon Isatoic Acid. 



Basic substances decompose isatoic acid likewise with evolution of 

 carbonic acid ; since this takes place even at a low temperature, it 

 has not been found possible to prepare salts of isatoic acid, as these 

 undergo immediate decomposition into salts of carbonic and of anthra- 

 nilic acids.* 



Isatoic acid, when heated with baryta-water, yielded besides car- 

 bonate of baryta the salt of anthranilic acid, which was extracted by 

 saturating the solution with acetic acid and then shaking up with 

 ether ; its melting point, as well as that of its hydrochloric acid com- 

 pound, conclusively proved that it had been formed. 



The action of ammonia on isatoic acid is to this extent different, that 

 not the ammonium salt of anthranilic acid, but its amide, which, so 

 far as my knowledge goes, is not yet known, is formed. 



Isatoic acid is readily taken up by aqueous ammonia ; the solution 

 immediately contains carbonate of ammonia, and after some time 

 solidifies to a mass of yellow crystals, which, after being redissolved 

 in hot water, separate out from the latter in glancing mother-of-pearl 

 plates ; the mother- liquor yields, on evaporation, a further quantity. 

 This compound, which is extremely soluble in warm water and in 

 alcohol, melts at 108°, and distils, with slight decomposition, towards 

 300°. Chloroform is a capital solvent for it, and from this it crystal- 

 lises in large white plates ; it is difficultly soluble in ether and hardly 

 at all in benzol. 



Analysis of Anthranilic Amide. 



I. 0'346 gram substance, dried over sulphuric acid, gave 0*776 gram 

 C0 2 and 0195 gram H 2 0. 



II. 0155 gram gave 0*350 gram C0 2 , and 0*084 gram H 2 0. 



III. 0*234 gram gave 41 c.c. N at 17° and 759 mm. pressure. 



IV. 0*353 gram gave 0793 gram C0 2 , and 0*200 gram H 2 0. 

 From this follows : — 



# That, on heating isatoic acid with soda-lime, anilin is set free, is explained by the 

 previous formation of anthranilic acid, whose decomposition product it is. 



