Codeine-N-oxide sulphonic acids

An isomer of 1-nitrocodeine, a-nitrocodeine can be prepared from codeine-N-oxide sulphonic acid. It gives 1-aminocodeine on reduction. Nitration of dihydrocodeine [241] and dihydrocodeine sulphonic acid [341] gives 1-nitrodihydrocodeine. 

When codeine-N-oxide is sulphonated, two isomeric codeine-N-oxide sulphonic acids, a- and /3-, are obtained the former being transformed to the latter by alkali. Both yield the same codeine sulphonic acid on reduction with sulphurous acid, ex- and /3-Codeine-N-oxide sulphonic acids and codeine sulphonic acid are converted to codeine by superheated steam and to /3- and y-codeine sulphonic acids by cold concentrated sulphuric acid [339, 350],... 

Nitration of codeine sulphonic acid affords 1-nitrocodeine [339, 350], whilst nitration and sulphurous acid reduction of a-codeine-N-oxide sulphonic acid gives a-nitrocodeine, which can be reduced to 1-amino-codeine [339, 350, 341], Bromination of the a-N-oxide sulphonic acid gives a perbromide of unknown constitution [339, 350] that is reduced to bromocodeine dibromide C18H20O3NBr3 [295]. 

The isomerio codeine-N-oxide sulphonic acids are not derived from i/r-oodoine, as i/r-codeine-N-oxide sulphonic acid is different from both [341]. It has boon suggestod that their structures are [xlu] and [xnn] [330]. 

Codeine-N-oxide sulphonic acid on heating with potassium chromate is converted to norcodeine sulphonic acid, which yields norcodeine on heating with superheated steam [352] (the nature of this change was not at first appreciated [339, 350]). Codeine-N-oxide likewise yields norcodeine and formaldehyde when oxidized with potassium chromate [352]. 

Two sulphonic acids are obtained by the sulphonation of i/<-codeine-N-oxide [295, 341] and bromination of these, followed by decomposition of the perbromide with sulphurous acid, gives bromo-i/i-codeine dibromide, C HgoOjNBrj, which can be reduced catalytically to tetra-hydro-i/ -codeine [295],... 

Two sulphonic acids result from the sulphonation of allo-i/ -codeine-N-oxide, and these on bromination and reduction of the per bromide are converted to bromoallo-i/r-codeine dibromide [295]. 

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