Apomorphine dimethyl ether

The Emde reduction of apomorphine dimethyl ether methochloride affords the dihydromethine [ix] [69]. 

Two syntheses of apomorphine dimethyl ether have been recorded, as follows. 

The alkaloids of stephania japonica apparently contain bases of the apomorphine group. Kondo and Sanada [96-97] have shown that desoxyepistephanine methiodide is the optical antipode of apomorphine dimethyl ether methiodide. 

Dimethoxy-8-vinylphenanthrene [xlvih] is the end-product of exhaustive methylation of apomorphine dimethyl ether. It can be oxidized to the 8-carboxylic acid [xlix] [64-65], which oan be converted via the amine to 3 4 8-trimethoxyphenanthreno [l] [66], identical with an authentic spcoimon [07] (see Chap. XXII). 

Apomorphine dimethyl ether, K4.8 C19H21NO3 Pronuciferine, K3.12 Thebaine, K4.6... 

The two phenolic groups differ markedly in reactivity. Methylation of apomorphine affords apomorphine-3-methyl ether, identical with apo-codeine, which on further methylation gives apomorphine-3 4-dimethyl ether [18]. A monoacetyl-derivative has also been prepared [63]. 

A similar ring-fission occurs when apomorphine is heated with acetic anhydride and hydrochloric acid [71] and when the mono- and dimethyl ethers are heated with benzoyl chloride [72], Another reaction that involves fission of the nitrogen ring is the reaction between diben-zoylapomorphine and cyanogen bromide, which results in [xii] [73]. Other tetrahydroisoquinoline derivatives also suffer ring-fission with this reagent [74-76]. 

Demethylation of morphothebaine can be effected by heating with dilute hydrobromic acid at 170° C., the product being 6-hydroxyapo-morphine, which reduces silver nitrate very rapidly and is oxidized by atmospheric oxygen even more readily than apomorphine [16]. Morphothebaine and its dimethyl ether give dark green amorphous substances on oxidation with alcoholic iodine [5],... 

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