354 Mr. C. H. Browning and others. Relationships betiveen 



diphenylmethane, prepared by the action of formaldehyde on dimethyl aniline 

 in presence of dilute sulphuric acid was nitrated in the cold with potassium 

 nitrate and cone, sulphuric acid and the purified dinitro-derivate, m.p. 141°-2°, 

 reduced with stannous chloride. After reduction the base m.p. 141°-2° 

 was precipitated with caustic soda and extracted from the stannous 

 hydroxide with alcohol. It was converted into the acridine compound m.p. 

 181°-2° as described under tetraethyldiamino acridine (see below) and the 

 latter into the methosulphate. From the solution of the methosulphate 

 potassium nitrate precipitates the methonitrate in red needles from which the 

 methoxide was obtained as a hygroscopic mass on the addition of ammonia. 

 The methochloride is too soluble and hygroscopic to be separated, and closely 

 resembles the corresponding ethyl derivative described below. 



[55.] 2.7.7 etraethyldiamino-acridine was prepared by the above method 

 using diethylaniline in place of dimethylaniline. The tetraethyldiamino 

 diphenyl methane is a colourless liquid, which boils at 285°-290° at 10 mm. 

 and 305°-310° at 20 mm. pressure. The yield from 100 grms. of diethyl- 

 aniline was 50 grm. of the diphenylmethane derivative. On nitration it 

 formed a dinitro derivative which crystallised from acetic acid in orange red 

 plates m.p. 118°-119°. The latter was reduced with tin and hydrochloric acid 

 and the tin partly removed by hydrogen sulphide. The filtered solution on 

 evaporation left a colourless, resinous mass of the hydrochloride which 

 contained some tin salt. 2 grms. of the hydrochloride were heated with 

 4 c.c. of cone, hydrochloric acid diluted with 12 c.c. of water at 140° for 

 6 hours in a sealed tube. The red coloured contents of the tube were 

 extracted with boiling water in which they dissolved leaving very little 

 residue, and to the hot solution ferric chloride solution was added until no 

 more precipitate was formed. After the addition of a solution of common 

 salt, which throws down a further quantity of the acridine compound, the 

 mixture was filtered after cooling and washed with salt solution. The deep 

 red solution was made alkaline with ammonia which precipitates the yellow 

 base. The latter was filtered and washed and dissolved in hydrochloric acid. 

 On concentrating the solution, the hydrochloride crystallises in red crusts 

 with a green iridescence. The crystals dissolve in water with a bright orange 

 colour. 



[56. 57.] 2.7.Tetraethyldiamino-acridine methochloride and methonitrate. — 

 To prepare the methonitrate an excess of dimethyl sulphate was added to the 

 finely powdered base in a small basin. The mixture becomes hot. After 

 heating for a time on the water-bath, the methosulphate crystallises. Water 

 was then added, and heating continued until the excess of methyl sulphate 

 was decomposed and a clear red solution obtained. On the addition of a 



