SYNTHESIS 



The following reactions relating to the synthesis of pyridoxine 

 were protected by Hoffmann-La Roche : 



CHgOEt 



CH 



PCI5 



CH^OEt 



CN 



3\ 



'OH 



N 



CH3L >C1 



CH^OCeHs 



(^)" C10C/\CN 



NaNa 



N 



N,OC 



CH 



CI 



CH. 



CH.OCeHs CH.OCeHfi 



CN EtOH EtOOC.NH^\cN 



V 



CI 



CH, 



iCl 



^N 



R 



EtOOCrr^|CN 



! 



KsFeCys 



CH. 



H 



EtOOCi 



CH, 



R 



CN 



(R = alkyl, aryl or 

 aralkyl) 



H 



id) 



HOOC 



CH; 



HNO2 



COOEt 



I 

 CH2 



COOEt C . COOEt 



I il 



3CH CH 



CH3 

 CHgOCeHg 



CN 



H 



^ HO 



COOEt 



OOEt — 



COOEt 



CH 



3\ / 



N 



CH3 



CHgOCeHg 



HO 



CH 



COOEt 



ch/ \i 



PCI5 



V 



OH 



ClOC 



CH 



NH..NH.NH3.NH.CO 



EtOOC . NH 



CH 



CH^OCeHs 



CN 



^S, 



JCl 



CN 

 CI 



jr EtOOC . NH 

 CH 



CH^OCeHg 



CN 



CH; 



CH^OCeHs 



ici 



'N 



CH2NH2 HNO2 



N 



CHgOCgHg 

 EtOOC . Nh/\,CH20H 



CH.OH 



HBr H2N 



CH, 



CH, 



'K 



'K 



^^Z 



jCH^OH Hjjo^ HO[^ ^iCHaOH 

 ^N^ 



Alternatively, the final hydrolysis can be effected with hydro- 

 chloric acid and the diazotisation with silver nitrite. ^^ 



20 



305 



