II. CHEMISTRY 407 



lately and altcrwanls to connect botli parts. It is also possible to synthesize 

 one of the iniclei with an extra side hianch and al'tci-wards to hiiild iij) tin; 

 other lini:; tVoni this side branch. 



For synthesizing the pyriniidine part, etliyl formate and /:i-ethoxyethyl- 

 propionatc may be condensed with Na. 



HCOOC0H5 + CH..OC.,n,CH2COOC2H5 + Na -^ NaOCH 



C— CH2OC2H5 



COOC2H 



2A15 



This product is condensed with acetamidine. 



OH 



/ 

 N=C 



I I 

 ^ CH3C C— CH0OC..H5 



II II 

 N— CH 



The hydroxyl group is converted into an XH2 group by treating first with 

 POCI3 and then with NH3. The ethoxy group is converted into a bromide. 

 Thus the final product is : 



NHrHBr 



/ 

 N=C 



I I 



CH3C C— CH2Br 



II II 

 N— CH 



The thiazole moiety may be synthesized in several ways (cf. Buchman'"'^ 

 and Clarke and Gurin'^). The method of Buchman consists in condensing 

 thioformamide ^\ith bromoacetopropanol. 



By heating the hydrobromide of the pyrimidine compound with the 

 thiazole compound, the thiamine hydrobromide is formed. 



The bromide hydrobromide may be converted into the chloride hydro- 



^2 E. R. Buehman, J. Am. Chem. Soc. 58, 1803 (1936). 



" H. T. Clarke and S. Gurin, /. Am. Chem. Soc. 57, 1876 (1935). 



