RECENT WORK ON THE MORPHINE GROUP 281 



solution of chloride of zinc act, according to Wright 1 and his 

 co-workers, in a twofold manner upon morphine. Under certain 

 conditions a heterogeneous mixture of condensation products 

 is obtained — trimorphine, tetramorphine, etc. — whilst under other 

 conditions a molecule of water is abstracted according to the 

 equation : 



C I7 H 19 O a N = C 17 H l7 0,N + H 2 



Morphine Apomorphine 



Apomorphine, the product of this reaction, is an amorphous 

 base, slightly soluble in water, and very readily oxidisable. 

 Its physiological properties are quite different from those of 

 morphine ; it is not a narcotic but a very powerful emetic. 



The Constitution of Morphine 



Turning now to the question of the structure of the morphine 

 molecule, we find that the three oxygen atoms exercise different 

 functions. One belongs to a phenolic hydroxyl group, confers 

 upon morphine its acidic character, and has its hydrogen re- 

 placeable by a metal, an acid radicle, or an alkyl radicle. It is 

 this hydrogen atom which has been substituted by a methyl 

 group in codeine, which is therefore the methyl ether of mor- 

 phine — a relationship discovered in 1869 by Matthieson and 

 Wright, 2 and represented by the formulae : 



C I7 H l7 ON(OH), C, 7 H l7 ON(OH)(OCH 3 ) 



Morphine Codeine 



Morphine was converted into codeine in 1881 by Grimaux, 3 who 

 treated it with methyl iodide in the presence of alkali. 



C, 7 H 17 ON(OH), + CHJ + KOH = C )7 H 17 ON(OH)(OCH 3 ) + KI + H.O 



Morphine Codeine 



In view of this near relationship, it is obvious that the 

 elucidation of the constitution of morphine establishes that of 

 codeine also. 



That both morphine and codeine contain also an alcoholic 

 hydroxyl group is shown by the investigation of Matthieson 

 and Wright, 4 who obtained, by the action of concentrated 



1 Chemical News, 19, 289, 302 ; 27, 317. Ber. 2, 286, 336 ; 4, 121 ; 5, 336, 538, 

 1 109 ; 6, 828. 



2 Proc. Roy. Soc, Ann. Spl. 7, 364. 



3 Compt. rend. 92, 1140, 1228 ; 93, 67, 217, 591. 

 * Loc. cit. 



