CHEMISTRY OF PURINES AND PYRIMIDINES 



91 



NH, 



CHo 



CHa CH2CH2OH CH2OH 



\ / HO i 



c=c 



CH3 



N 



\ 



c— s 



CH3 



/\N' 



— CH2OH 



XVI 



Thiamine 



XVII 



Pyridoxine 



HO 



CH2NH2 



-CHoOH 



CH3 



XVIIa 

 Pyridoxamine 



XVIII with chloromethyl ether). This instability of a pyiimidine-carbinol linkage has 

 been found to be peculiar only to the hydroxymethji at position 5, since such a group 

 at position 4 (or 6) or 2, as in 4-h3-drox_ymethylthymine*^' ** and 4-hydroxymethyl- 

 uracil*' (originally considered as the simplest "nucleosides" of thymine and uracil, 



OH 



OH 



OH 



CH2OH 



dil. acid 

 or alkali 



hot H2O 



N 



Sn 



CH3 



HCl 



N 



HO CH3 



XVIII 



HO CHa 



XIX 



OH 



CH2NH2 



HO 



/Vn/\ 



HO CH3 



XX 



OH 



CH2OH 



N 



\^/ 



N 



HO 



/^N 



XXI 



XXII 



respectively), 2-methyl-4-h3'droxy-6-hydroxymethylp3'rimidine*^ and 2,6-bis(hydroxy- 

 methyl)-4-hydroxy-5-methylpyrimidine,*' is not split off by hot water or hot mineral 



85 T. B. Johnson and L. H. Chernoff, J. Biol. Chem. 14, 307 (1913). 



86 T. B. Johnson and L. H. Chernoff, J. Am. Chem. Soc. 35, 585 (1913). 

 8^ T. B. Johnson and L. H. Chernoff, J. .4m. Chem. Soc. 36, 1742 (1914). 



88 G. E. McCasland, D. S. Tarbell, R. B. Carlin, and N. Shakespeare, J. Ayn. Chem. Soc. 

 68,2390 (1946). 



89 G. E. McCasland and D. S. Tarbell, J. A771. Chem. Soc. 68, 2393 (1946). 



