Sinomenine methine

Sinomenine roseomethine [xxix] (initially called /3-sinomenine methine [17]), which is obtained by the slow isomerization of the ac/tromethine on standing for several years, also results from the degradation of sinomenine methiodide with five equivalents of 5 per cent, sodium hydroxide. The base is yellow in colour and gives an intense maroon haloohromio solution in oonoentrated sulphurio aoid [17, 38]. 

Dimethoxy-4 6-dihydroxyphenanthrene (sinomenol) [xc] is obtained when sinomenine [lxxxix] [98-99], and when the three sinomenine methines, [xci], [xoii], and [xcm] [100], are boiled with 66 per cent, potassium hydroxide. It gives a dimethyl ether [dimethyl-sinomenol] [98], also accessible from sinomenine methyl ether [101], and a dibenzoyl-derivative [98], which also results when sinomenine or the achro-methine [xci] is heated with benzoic anhydride at 160° 0. [100-102]. 

In marked contrast to codeinone [lii], of which it is a derivative, 1-bromosinomeneine [cm] can be degraded to methine bases, of which two are known, viz. 1-bromosinomeneine methine [crv] [107] and 1-bromodehydrometasinomenine methine [cv] [111]. The acetolysis of 1-bromosinomeneine [cm] affords 1-bromodiacetylsinomeneine [ovi] together with a small quantity of 1-bromodiacetylsinomenol [cvn], which is also obtained by the acetolysis of 1-bromosinomenine, 1-bromo-sinomenine methine, 1-bromosinomenein methine [civ] [112], and 1-bromodehydrometasinomenine methine [cv] [111]. Catalytic reduction of [evil] yields diacetylsinomenol [112]. 

Sinomenine m oZeomethine [xxx] (initially called sinomenine a-methine [17]) is obtained in 20 per cent, yield when sinomenine achro-methine is heated with 10 per cent, sodium hydroxide [38] and also, in low yield, when sinomenine methiodide is degraded [17]. Its methio-dide, formed in almost quantitative yield by the action of cold 10 per cent, sodium hydroxide on sinomenine ac romethine methiodide, is degraded by hot alkali to sinomenol. Sinomenine w oZeomethine gives an intensely blue halochromic solution in concentrated acid solution [38], The thebainone analogue, thebainone-B methine [xxxi], has also been prepared [39],... 

E. Exhaustive methylation of desmethoxydesoxydihydro-sinomenine [xiv], the optical antipode of tetrahydrodesoxycodeine, leads to the methine [xliii], dihydromethine [xliv], 9 10-dehydro-(—)-thebenane [xlv], and (—)-thebenane [xlvi] [18, 30, 48], which form raoomates with the compounds prepared from tetrahydrodesoxy-oodeino [50]. Dosmothoxydosoxydihydrosinomenine dihydromothino... 

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