CHEMICAL CONSTITUTION 



by the action of sodium in liquid ammonia. The constitution of the 

 pyrimidine was established by synthesis.^ By a similar synthesis/ 

 5-ethoxymethyl-4-hydroxy-2-methyl-pyrimidine was prepared and 

 this, on treatment with sodium sulphite, yielded 4-hydroxy-2-methyl- 

 pyrimidyl-5-methane-sulphonic acid, identical with the compound, 

 C6H8N2SO4. The primary cleavage product, CgHgNaSOg ,was there- 

 fore presumed to be 4-amino-2-methyl-pyrimidyl-5-methane-sulphonic 

 acid : 



N=:C— NHj 



CH3— C C— CH.— SO3H 



N— CH 



The other primary cleavage product, CgHgNSO, was oxidised with 

 nitric acid, '^ giving 4-methyl-thiazole-5-carboxylic acid, identical with 

 a compound prepared in 1890 by M. Wohmann.^ This substance had 

 also been obtained by A. Windaus and his colleagues ^ by the oxidation 

 of aneurine with nitric acid, but they failed to recognise the presence 

 of the thiazole nucleus. 



Since the compound, CgHgNSO, contained an alcoholic hydroxyl 

 group that could be readily replaced by chlorine,^ it was assumed to be 

 5-j8-hydroxyethyl-4-methyl-thiazole and the correctness of this assump- 

 tion was established by H. T. Clarke and S. Gurin,^^ who synthesised 

 it by a method described below. 



The first formula for aneurine, suggested by Williams before the 

 constitution of the pyrimidine half was known, was 



N=rC— NH2 



CH, 



I I /C.=C— CH2— CH2OH 

 CH C N/ I 



II II ci^^^-s 



N— C— C2H5 ^^ HCl 



This was subsequently revised but, in the meantime, A. Windaus and 

 his colleagues ^^ put forward a very similar formula : 



CH3 



I ' .C=C— CH2— CH2OH 



CH3— c c n{ I 



II II ci^^^-s 



N— C— CH3 ^^ HCl 



This formula was also erroneous, though in an LG. patent ^^ protecting 

 the preparation of a substance of this structure it is claimed to have 

 vitamin Bj activity ! 



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