Codeine ultra-violet spectrum

The absorption spectrum of morphine has been determined by Hartley [594], Mayer (in sulphuric-nitric acid) [595], and Kitasato [596], and the ultra-violet absorption spectrum (shown in comparison with that of codeine in Chap. IV) by other workers [597-602],... 

Thermochemical studies have been made by Leroy [394-5], The absorption spectrum of codeine in the visible [396-7] and in the ultraviolet [398-9] has been determined. The ultra-violet absorption curve, compared with those of morphine and thebaine is given in Mg. 1. That of ethylmorphine is closely similar [400]. 

N ic opine was first isolated by Dobbie and Lauder from the last mother liquors from the processing of the opium alkaloids after all other bases had been eliminated [1], This remains the only source of the base. The method of isolation has since been improved and the alkaloid can ho separated from codeine through the sulphates [2], The base was first allotted the formula C18H2404N and the name hydroxycodeine it was shown to contain one —OMe, one —NMe, and to be a tertiary base. Its colour reactions and ultra-violet absorption spectrum are practically idontical with those of codeine [1]. 

Codeine dihydromethine [xn] has now been prepared by the sodium-ammonia reduction of codeine methiodide, together with dihydrodesoxy-codeine-C dihydromethine [xiii]. Both [xii] and [xni] result from the sodium and liquid ammonia reduction of a-codeimethine [xiv] [2] (cf. p. 106). The sodium and liquid ammonia reduction of dihydrocodeine methiodide affords a-tetrahydrocodeimethine, and the reduction of /3-codeimethine [xv] yields neopine dihydromethine [xvi]. When the methiodide of the latter is heated with sodium cyciohexyloxide in cyciohexanol a mixture of methyl-morphenol [xvn] and (-f-)-6-hydroxy-3-methoxy-5 6 7 8 9 10-hexahydro-phenanthrylene-4 5-oxide [xviii] is obtained. The latter structure is assigned to the product on account of the close resemblance of its ultra-violet absorption spectrum to that of a-codeimethine. This represents a new type of degradation with hydrolytic scission of the side-chain [2]. Metathebainone methine has also been degraded in this way [2]. 

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