ANEURINE (thiamine) 



17. J. R. Stevens and G. A. Stein, /. Amer. Chem. Soc, 1940, 62, 



1045. 



18. Research Corporation, B.P. 547664. 



19. Roche Products, B.P. 549306. 



20. I.C.I., B.P. 552617. 



21. Roche Products, B.P. 550197. 



22. Roche Products, B.P. 554428 ; U.S.P, 2397333. 



23. Roche Products, B.P. 559106. 



24. Roche Products, B.P. 588806. 



25. R. Grewe, Z. physiol. Chem., 1936, 242, 89. 



26. H. Andersag and K. Westphal, Ber., 1937, 70, 2035. 



27. I.G., B.P. 473193, 475559, 475507- 



28. I.G., B.P. 456751. 



29. I.G., B.P. 471416. 



30. Chinoin, B.P. 538743. 



31. G. V. Tschelintzev and Z. V. Benevolevskaja, /. Gen. Chem. Russ., 



1944, 14, 1 142. 



5. PROPERTIES OF ANEURINE 



Aneurine hydrochloride is 3-(4'-amino-2'-methyl-pyrimidyl-5'- 

 methyl)-5-/8-hydroxyethyl-4-methyl thiazolium chloride hydrochloride. 

 It forms white monoclinic plates generally in rosette-like clusters. It 

 is said to be odourless when pure, but generally has a slight smell of 

 bran. It is readily soluble in water {ca. i g. per ml.), less soluble in 

 methyl alcohol, 95 % ethyl alcohol (i g. per 100 ml.) and absolute 

 ethyl alcohol (i g. in 315 ml.), and insoluble in ether, acetone, chloro- 

 form and benzene. It crystallises from aqueous alcohol as the hemi- 

 hydrate, m.p. 248° to 250° C. with decomposition. The crystals were 

 originally described as monoclinic,^ but subsequently three different 

 crystalline forms were described. ^ Form I is orthorhombic and form 

 II monoclinic, and the latter is converted into the former in solutions 

 up to 80° C. The reverse change occurs in the solid phase at 182° C. 

 Form III has the same optical properties as form II, but the crystals 

 have a different shape ; this is the least stable form. 



Aneurine hydrochloride has a characteristic absorption spectrum 

 in 0-005 ^ hydrochloric acid, with a maximum at 247 m/z, at which 

 wave-length Eicm. ^^ 425 to 450. It is optically inactive. 



When a solution of aneurine hydrochloride is allowed to stand for 

 two or three days with a solution of sodium bisulphite, it gives a 

 quantitative yield of the sparingly soluble 4-amino-2-methyl-pyrimidyl- 

 5-methane-sulphonic acid. When a solution of aneurine hydro- 

 chloride in dilute hydrochloric acid is treated with formaldehyde and 

 diazotised aniline, a pink colour slowly develops and when the solution 

 is shaken with isobutyl alcohol, the colour passes into the alcoholic 



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