CHa 



I 

 CH3 . CO 



O.N 



CHaOEt 



/ 



PYRIDOXINE 



CHaOEt 

 NcN 



+ 



CH2 . CN 



io 



HN03^ 



0,N 



CH 



NHa 

 CHaOEt 



/\ 



CH 



CHgOEt 



CN 

 CI 



+ Pt 



CH 



HO 



CH, 



H 



CHaOEt 

 CN 



CH^Br 



AcsO CH 



3\ 



CHaOEt 



|CN 



N'^^'^O 



ii 



PCI5 



Ha + Pt H2N1 



CH 



CH^OEt 

 NCH.NH, 



+ Pd-C 



HNO2 



CH2OH HBr 



HO 



CH 



N' 



''X. 



H2O 



CH^OH 



H0/\. 



+ AgCl 



CH 



»\_ 



N" .N 



Subsequently, improved modifications of this method were devised. 

 The synthetic material made by these workers was tested by Reedman 

 et alP- and shown to have the same degree of vitamin Bg-activity as 

 the natural vitamin, being fully active in rats in a dose of 100 /zg. 



The synthetic methods adopted by Kuhn et al.^ and by A. Ichiba 

 and K. Michi * were different from those used by the American workers 

 and involved the use of 4-methoxy-3-methyl-isoquinoline as starting 

 material. Ichiba and Michi used oxidation with alkaline potassium 

 permanganate solution to effect the first step, whilst Kuhn et al. 

 nitrated the isoquinoline, reduced the nitro compound to the corre- 

 sponding amino compound and then oxidised the latter with perman- 

 ganate. The remaining stages used by these two groups of workers 

 were identical, namely : 



COOH CN 



CH, 



OCH3 



N 



CH,UI 



COOH NH, 



CH3o/\cN 



Pd-C 



CHgOj 



CH, 



CHaNHa 



^^CH^NHa 



HN02 



CH^Br 



CH.Oj 



chJ 



CHaOH 

 ^"llCHaOH 



11 



HBr HO 



CH3I 



CH3r 



302 



V 

 CH20H 



H0/%CH20H 



CH 



N 



