344 Mr. C. H. Browning and others. Relationships between 



[4—11.] The Aminoquinolines and the Methochlorides. — The o, m, p and a 

 aminoquinolines were prepared from the corresponding nitroquinolines by 

 reduction, the latter being obtained from the nitranilines by Knueppel's 

 modification of Skraup's method* in which anhydrous arsenic acid is employed 

 as oxidising agent. The ??i-nitraniline gives rise to two nitroquinolines, the 

 nieta and ana derivatives, which were separated by crystallisation from alcohol 

 in which the a?i«-conipound, m.p. 65°, dissolves more readily than the meta, 

 m.p. 132-4°. In this way the meta-compound was obtained quite pure : but 

 the ana-compound after repeated crystallisation melted at 48-50°. 



The reduction of the o- and ^-nitroquinolines was effected by a modification 

 of the process described by Knueppel with iron and hydrochloric acid. The 

 product in the case of the ortho-compound was evaporated to dryness and the 

 residue extracted with alcohol in which the hydrochloride dissolves. The 

 solution was made alkaline and distilled in steam. The distillate was acidified 

 with hydrochloric acid and evaporated to dryness. The base was separated 

 by adding caustic soda and extracting with ether. On removing the ether, 

 the base separated in almost colourless crystals, which after recrystallisation 

 melted at 65°. In the case of the para-compound, the product after 

 reduction was made alkaline and extracted with ether. It melted at 108°. 

 The m- and ct-compouuds were reduced with tin and hydrochloric acid. 

 Calculated quantities of the materials were introduced into a flask and heated 

 for a short time in the water-bath until the reaction began when the flask 

 was removed and if necessary cooled. The tin double salt of the meta-com- 

 pound, which crystallises on cooling, was separated, decomposed with excess 

 of alkali and extracted with ether. The product, crystallised from alcohol, 

 melted at 188-190°. In the case of the ana-compound the double salt does 

 not separate readily and the solution was, therefore, concentrated on the 

 water-bath. The base was extracted with ether after the addition of alkali 

 and on crystallisation from alcohol melted at 107°. The acetyl derivatives 

 were prepared by boiling gently for \ hour 1 grm. of the base with 1 grm. 

 of fused sodium acetate and 4 c.c. of acetic anhydride. After cooling, water 

 was added and then ammonia gradually until alkaline when the acetyl 

 derivatives crystallised. They were recrystallised from dilute alcohol or 

 water from which the m-, p- and a-compounds separated in colourless 

 plates or flattened prisms ; the o-compound had a faint yellow colour. The 

 following are the melting points: — 



* 'Ber.,' vol. -29, p. 703 (1896) ; ' Aimalen,' vol. 310, p. 75 (1900). 



