86 BIBLIOGRAPHY OF 



KNORR, L., 1886. 



Ann. Chem. 238, 137-219; J. Chem. Soc. 52, 601 ; Ber. 20, 259 (C). 



Synthetical Experiments with Acetoacetic Ester. Part III. 



The compounds obtained from the action of phenylhydrazin on 

 acetoacetic ester, heretofore described by the author as quinizin deriva- 

 tives are now considered pyrazolone derivatives, pyrazolone being 



CH 2 - CO 



I > NH. Thus antipyrin is phenyl-dimethyl pyrazolone 



C H = N 



[1:2:3] and not di-methyl oxyquinizin Phenylmethyl pyrazolone is 

 described. Phenyltrimethyl pyrazolone [1:3:4:4] obtained from di- 

 methyl-acetoacetic ester melts at 55-56 boils at 300 to 303 and is 

 isomeric with methyl antipyrin. Disphenyl-methyl pyrazolone, [1:3:5] 



CO CH CH CO 

 C 6 H 5 N< I I >NC 6 H 5 , and a number of its 



I I 



CH 3 CH 3 



derivatives are produced and described, among which is pyrazol blue, 

 obtained from the above by abstracting the two hydrogen atoms from 

 the CH groups. Some of the aromatic and nitrogen compounds of 

 the pyrazolones are described and also some halogen compounds of 

 antipyrin. 



CONRAD, M. and M. GUTHZEIT, 1887. 



Ber. 20, 151-154; J. Chem. Soc. 52, 502; Jsb. Chem, 1887, 1818 ; 

 Bull. Soc. chim. 48, 154. 



Dimethyl-pyrondicarboxylic Ester 



This substance, obtained from cupracetoacetic ester and carbonyl 

 chlorid, formerly called dehydro-carbonyl-diacetoacetic ester is now 

 considered to be a derivative of pyron, 



O 



/ \ 

 HC CH, 



II II 



HC CH 



\ / 



C 



II 



O 



