422 



SCIENCE. 



[N. S. Vol. VIII. No. 196. 



mann's original conception, viz.: that the 

 jp-amidophenol had its origin in the phe- 

 nylhydroxylamine — the intermediate prod- 

 uct. The question continued to interest 

 chemists to such a degree that Lob sus- 

 pended nitrobenzene in fuming hydrochloric 

 acid or in alcoholic hydrochloric acid, or in 

 mixtures of hydrochloric acid and acetic 

 acid, and reduced it electrolytically. The 

 products were p- and o-chloraniline. The 

 corresponding bromanilines were obtained 

 when hydrobromic acid was used. Lob 

 and Gattermann concluded then that the 

 reduction was correctly represented in the 

 following equations : 



1. CsHsNOj + 4H + HCl = CcHjNHCl + aH^O, 



2. CcHbNHC I = CsHiClNH; ; 



0- and ^-Aniline 



while with Elbs the course of reduction 

 would be represented in this manner : 



1. aH5N02 + H2 = C6H5- 



/% 



-N 



N — C„H5 + H,0 



2. CsHs - N - N. CsHj = CeH^N = N. CsH,. OH 

 3. CsHsN = N. CgHiOK + 2HC1 = CeH^NHCl 

 + HC1NC6H40H = 

 CeH^ClNHj, + CaHa (OH) CI. NH, 

 a b 



A second body, (b) chloramidophenol, 

 should be produced if the view of Elbs was 

 correct. It was, however, at no time dis- 

 covered in the reaction mass, thus affording 

 additional evidence of the correctness of 

 the first idea. It is not necessary for me 

 to submit all the evidence pointing to the 

 presence of the extremely unstable inter- 

 mediate compound CgH^NHCl, which re- 

 arranged itself into the chloranilines : 

 enough to know that it is very convincing 

 and has been further corroborated by the 

 isolation of the body C,H,NC] CO. CH^, 

 observed by Bender. 



Gattermann, seeking further support for 

 his views, introduced benzaldehyde into the 

 reduction mixture at the very outstart. He 

 obtained benzylidene hydroxylamine, a con- 



densation product previously prepared by 

 Bamberger upon mixing benzaldehyde and 

 phenylhydroxylamine : 



CeHjNH.OH + CsHj.CHO = 



C^Hs.N. — CH.CjHj + HjO. 

 Further, o-nitrotoluene and benzaldehyde 

 gave benzylidene-o-tolyl hydroxylamine, 

 and VI- and p-nitrotoluenes the correspond- 

 ing bodies, thus completely establishing the 

 point under discussion. The reduction of 

 nitro-ketones gave the expected derivatives 

 ofp-amidophenol, e. g'.,m-nitroacetophenone 

 yielded amido-oxyacetophenone— 



NOAHiCOCH, = 



CO.CH.. 



Similar results were realized with ?n,-nitro- 

 benzophenone and with ?)i-nitrophenyl-j3- 

 tolyl ketone. 



Time forbids more than mere mention of 

 Lob's reduction of the three nitrobenzoic 

 acids and the theory he has proposed in 

 explanation of their reduction ; the hydro- 

 genizing of pyridine with the production of 

 piperidine; the obtainment of pipecolin© 

 from picoline ; the probable reduction of all 

 the higher homologues of pyridine; the 

 conversion of quinoline into its tetrahydride 

 and a trimolecular dihydroquinoline ; that 

 of quinaldine to its tetrahydride and tri- 

 molecular dihj^droquinaldine : Noyes and 

 Dorrance's reduction of nitro-bodies con- 

 taining substituents in the para-position, as 

 well as the reduction of p-nitro-benzoic acid 

 in acid solution by Noyes and Clements; 

 Ahrens' efforts to reduce nitriles to primary 

 amines ; the conversion of eugenol into iso- 

 eugenol and the electrolytic oxidation of 

 the latter to vanilline; Elbs' oxidation of 

 p-nitrotoluene to p-niti-obenzyl alcohol; that 

 of nitrosopiperidine to dipiperidyl ; that of 

 the toluene sulphonamides to benzoic sul- 

 phinides with the formation of saccharin, 



