ADENIN. 363 



Dibenzyl adenin, C5H3(C^H,)2N5 , is produced, according to Kruger, 

 in small amount in the preparation of the mono-benzyl compound. It 

 is best obtained by treating mono-benzyl adenin with benzyl chlorid ; 

 or by the action of benzyl chlorid on an alcoholic solution of adenin 

 and potassium hydrate. The free base is obtained by precipitating 

 a solution of the hydrochlorid with ammonium hydrate. It forms 

 fine silky needles which melt at 171° to a yellow fluid. It is easily 

 soluble in ether, very easily in alcohol. In cold water at 13.5° the 

 solubility is 1 : 13,300 ; in water at 100° it is 1 : 1300. A 1 per cent, 

 alcoholic solution gives reactions with silver nitrate, ammoniacal 

 silver solution, mercuric chlorid, copper sulphate, platinum chlorid, 

 and picric acid. Gold chlorid, lead acetate, basic lead acetate, give 

 no precipitate. 



The hydrochlorid, C5H3(C,H,)2N5.HC1, crystallizes in fine silky 

 needles, frequently in long prisms with a silky luster resembling that 

 of caffein. It is easily soluble in water and in alcohol ; insoluble in 

 ether. It is thrown out of water solution, in part, by the addition 

 of hydrochloric acid — a reaction not given by the mono-benzyl com- 

 pound. The melting-point is at 219°- 220°. 



The nitrate, C^'BiJ(^^JIj\'N ^ .HNO3 , crystallizes in fine, long glis- 

 tening needles, which are difiicultly soluble in cold dilute nitric acid. 

 It melts at 167° with evolution of gas. On decomposition with con- 

 centrated hydrochloric acid at 180°- 200° it yields the same prod- 

 ucts as mono-benzyl adenin (Kruger). 



9-methyl adenin, C5H^(CH3)Nj , was first prepared in a condition 

 of purity by Kruger. In 1897, Fischer' prepared the 7- and 9- 

 methyl adenins synthetically. The methyl adenin described by 

 Thoiss and prepared by the action of methyl iodid on adenin-silver 

 at 100° is probably an addition product, not methyl adenin. The 

 introduction of the methyl group in this way does not take place 

 readily, according to Kruger, owing to the formation of addition 

 products. This addition of methyl iodid can be overcome readily 

 by the presence of sodium alcoholate. This can be done by dis- 

 solving adenin in alcoholic sodium hydrate and then adding methyl 

 iodid and allowing to stand for some months, or better, by warming 

 under an inverted condenser. It crystallizes from water in anhy- 

 drous, long, silky needles or glassy prisms resembling caffein. On 

 drying in the air the silky luster disappears. It may crystallize with 

 one and a half molecules of water and does not melt at or below 270°. 

 According to Fischer, it melts at 308°— 310° (corr.) without decom- 

 position. It is rather difiicultly soluble in water, equally so in alka- 

 lis; and is soluble in 14 parts of hot water. The gold salt of 

 methyl adenin crystallizes in fine yellow lusterless needles. The 

 platinochlorid is rather difiicultly soluble in cold water and crystal- 

 lizes in bright four- or six-sided rhombic plates. A 1 per cent. 

 'Berkhle, 30, 2250 ; 31, 104, 112. 



