Thionyl chlonde

Because tertiary alcohols are so readily converted to chlorides with hydrogen chlo nde thionyl chlonde is used mainly to prepare pnmary and secondary alkyl chlondes Reactions with thionyl chlonde are normally carried out m the presence of potassium carbonate or the weak organic base pyndme... 

One Sanofi synthesis of enantiomerically pure (+)-clopidogrel (2) utilized optically pure (R)-(2-chloro-phenyl)-hydroxy-acetic acid (20), amandelic acid derivative, available from a chiral pool.18 After formation of methyl ester 21, tosylation of (R)-21 using toluene sulfonyl chloride led to a-tolenesulfonate ester 22. Subsequently, the SN2 displacement of 22 with thieno[3,2-c]pyridine (8) then constructed (+)-clopidogrel (2). Another Sanofi synthesis of enantiomerically pure (+)-clopidogrel (2) took advantage of resolution of racemic a-amino acid 23 to access (S)-23.19 The methyl ester 24 was prepared by treatment of (S)-23 with thionyl chlonde and methanol. Subsequent SN2 displacement of (2-thienyl)-ethyl para-toluene-sulfonate (25) assembled amine 26. 

From the acid chloride (prepared from the acid and thionyl chlonde) and aniline in benzene or in ether For directions and examples see Cheronis, p 445, Linstead, p 14, Shriner, pp 98, 200-1, Vogel, pp 369,458, Wild, p 182, P W Robertson, 7 Chem Soc, 115,1210(1919)... 

Carboxylic acid Thionyl Acyl chlonde Sulfur Hydrogen... 

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