RECENT ADVANCES IN SCIENCE 213 



ORGANIC CHEMISTRY. By P. Haas, D.Sc, Ph.D., St. Mary's 

 Hospital Medical School, London. 



The possibilities of the technical applications of acetylene have 

 been more than once referred to in these columns, and a recent 

 paper by Richard Meyer and Hans Wesche (Berichte, 191 7, 50, 

 422) indicates a further direction in which this hydrocarbon 

 might be utilised. One of the authors has for some years 

 past been making a study of the pyrogenic condensation of 

 acetylene, a subject which was originally investigated by 

 Berthelot in 1866. The method adopted has been to pass 

 acetylene alone or mixed with hydrogen over copper gauze 

 in tubes heated to 6oo° C, and in the earlier papers (191 2, 191 3, 

 and 191 5 ) the production of a number of different hydrocarbons 

 was described. The present paper is concerned with attempts 

 to prepare some of the phenolic and heterocyclic compounds 

 found in coal tar. It has been found that acetylene reacts 

 with hydrogen sulphide in presence of copper at 640-660 C. 

 to form thiophen and thionaphthen. Acetylene methane and 

 hydrogen sulphide gave thiotolen, thioxens, and thionaphthen. 

 Acetylene and ammonia gave pyridine, pyrrole, aniline, benzo- 

 nitrile, quinoline, anthracene, and fluorene. Acetylene and 

 steam reacted at 500-600 C, forming only a small quantity of 

 phenol. Acetylene steam and ammonia gave pyridine, aniline, 

 phenol, and much hydrogen cyanide. Aniline and steam react- 

 ing at 650- 700 C. gave a small quantity of phenol. Much of 

 the work done has been carried out with a view to throwing 

 some possible light on the origin of the various compounds 

 occurring in coal tar. A paper by Zanetti and Egloff (/. Ind. 

 Eng. Chem. 191 7, 9, 350) dealing with the thermal decom- 

 position of benzene at temperatures varying from 500-800 C. 

 is of some interest in this connection. The chief products of 

 decomposition are diphenyl, diphenylbenzenes, carbon, and 

 hydrogen, but no naphthalene or acetylene. Diphenyl begins 

 to be formed at 500 C, but the optimum temperature for its 

 formation is 750° C. Above this temperature diphenylbenzene, 

 carbon, and hydrogen are formed. Copper exerts no marked 

 action until the temperature exceeds 750 , when it favours 

 the formation of carbon. Iron and nickel likewise favour the 

 decomposition to carbon and hydrogen. 



A new type of ammonium compound is described by Schlenk 

 and Holtz {Berichte, 191 7, 50, 276). By shaking an ether 



