472 



SCIENCE 



[N. S. Vol. LIV. No. 1402 



pH 



CIL,C00NH,;Z±CH4C00H+NHr?CH,OOH r? CH,CONH,f H,0 





NH, 



NH' 



results point to the above mechanism for the reac- 

 tion. 



If this is accepted, it would seem that acetic acid 

 catalyzes the reaotion chiefly through its hydrogen 

 ions and ammonia through its amide, NH-, ion. 



Preparation of absolute alcohol: W. A. Notes. 

 Beilstein contains a statement that alcohol is dehy- 

 drated commercially by means of calcium chloride 

 but I have been able to find no other reference to 

 the matter in the literature. A careful study has 

 brought out the following: From strong alcohol 

 containing somewhat more than one mol of calcium 

 chloride for each mol of water present, alcohol of 

 99 per cent, or stronger may be distilled. On con- 

 centrating such a solution a solid alcoholate (not a 

 hydrate) separates and there is an equilibrium be- 

 tween the alcoholate and hydrate present. A quite 

 high temperature is required to expel the alcohol 

 from this solid but if enough water is added so that 

 about 5 mols are present for each mol of calcium 

 chloride, the alcohol may be distilled away com- 

 pletely at a temperature below 140°. The hydrate 

 of calcium chloride which remains is liquid at 100°, 

 or above, but solidifies at ordinary temperatures. 

 On the basis of the facts given, 99 per cent, alcohol 

 may be prepared, by means of calcium chloride, 

 without loss of alcohol. The remainder of the water 

 can then be removed by lime or by some other 

 method. 



S, 8-diamino-diIiydroquinine and 5, 8-diamino-6- 

 metlioxyqumoline , and their conversion into the 

 corresponding amino-hydroxy and dihydroxy bases: 

 Walter A. Jacobs and Michael Heidelbeegek. 

 5, 8-diamino-dihydroquinine, obtained by reducing 

 5-amino-8-p-sulfophenylazo-dihydroquinine (J. Am. 

 Chem. Sac, 1920, xlii, 2281) ; decomposes at 125- 

 40°, and yields a vermilion, crystalline tetrahydro- 

 bromide and a brown crystalline sulfate decompos- 

 ing at 220-7°. 5-hydroxy-8-phenylazo-dihydroqui- 

 nine {Ibid., p. 2280) yielded a crystalline double tin 

 salt of 5-hydroxy-8-amino-dihydroquinine, the base 

 and other salts being very unstable. Boiled with 

 1 : 1 hydrochloric acid the diamino compound 

 yielded the dihydroxy dihydroohloride, vermilion 

 needles decomposing at 208-11° (anhydrous), also 

 obtained from acid solutions of the amino-hydroxy 

 compound on long standing. For comparison the 

 series derived from 6-methoxyquinoline was also 



HVOH' 



prepared, 5, 8-diamino-6-methoxyquinoline forms 

 golden leaflets melting at 163-4°; 5-hydroxy-8- 

 amino-6-methoxyquinoline yellow crystals melting 

 at lS0-2°, and the 5, S-dUiydroxy compound yel- 

 low crystals melting at 195-7°. The lability of 

 the amino groups in these compounds as well as in 

 the previously reported dyes is thus shown to 

 be of a high order. 



The hydrogenaiion of dihydrocinchonine, chin- 

 chonine. and dihydroquinine: Waltek A. Jacobs 

 AND Michael Heidelberger. By reducing dihy- 

 drocinchonine with sodium in boiling amyl alco- 

 hol and converting into the hydrochlorides two 

 stereoisomeric hexahydro bases were isolated, in 

 which the 2'J alcoholic group had also been re- 

 duced. These a- and ^-hexahydrocinchonanes 

 (for terminology see J. Am. Chem. Soc, 1920, 

 xlii, 1492) were crystalline, and yielded charac- 

 teristic hydrochlorides, nitroso, benzoyl, and phen- 

 lyazo derivatives, thus showing the properties of 

 tetrahydroquinolines. From the mother liquors 

 a small amount of hexahydrocinchonine dihydro- 

 bromide was isolated. The a- and jS-compounds 

 were also obtained by reducing dihydrocincho- 

 nane. Cinchonine yielded an a-tetrahydrocineho- 

 nane, convertible into the a-hexahydro compound 

 with Pd and H, while the mother liquors also 

 reduced with Pd and H gave the a-, /3-, and 

 hexahydrocinchonine-compounds. Dihydroquinine 

 yielded chiefly hexahydroquinine dihydroehloride, 

 characterized by the nitroso and benzoyl deriva- 

 tives. 



05'^- 



HCHrCltj 



HeXo-liyMcocinclionane 



A new series of cinclw7ia-'ike alkaloids: the 

 dihydroquinieinols : Michael Heidelberger and 

 Walter A. Jacobs. Reduction of the quinicines 

 (quinotoxines) with palladium and hydrogen 

 gives rise to a new series of alkaloids with an 

 asymmetric secondary alcoholic group, thus re- 

 sembling the cinchona alkaloids themselves. Quini- 



