ACETO ACETIC ESTER 117 



BUCKA, K. AND CH. SPRAGUE, 1890. 



Ber. 23, 847-855 ; J. Chem. Soc 58, 796. 

 Action of Phenylhydrazin on Thioacetoacetic Ester. 



When these substances react in cold, glacial acetic acid in the pro- 

 portion of one molecule of thioacetoacetic ester to two molecules of 

 phenylhydrazin they form thiophenylmethylpyrazolone, 



C 20 H I8 N 4 S0 2 = | | 



N 



Ce H 5 Ce H 5 



| 



N 



/ \ / \ 



N CO OC N 



II I I II 



CH 3 C CH - S - HC C CH 3 



and not C 20 H 22 N 4 SO 4 as Michaelis and Philips state in their article 

 (*which see). It decomposes at 183 without melting, is soluble in 

 alkalis and forms stable salts with strong acids. When heated with 

 an excess of phenylhydrazin it goes over into phenylmethylpyrazolone- 

 ketophenylhydrazone which is the same as Michaelis' phenyl-methyl- 

 pyrazolonazobenzene, 



C 6 H 5 



N 



/ \ 

 N CO 



II I 

 CH 3 C - C = N N H C 6 H 5 



CLOEZ, C., 1890. 



Compt. rend, no, 583-586 ; J. Chem. Soc. 58, 739 ; Ber. 23, 284 (C). 



Hydroxytetric Acid. 



By treating methyl-acetoacetic ester with bromin dibrom-methyl- 

 acetoacetic ester, C 6 H 7 Br 2 (CH 3 ) O 3 , is formed, and when this is 

 treated with alcoholic potash, hydroxytetric acid, C 5 H 6 O 4 , is obtained, 



See page 116. 



