Page 17 - phytochemistry II -pharmD general

• Primary alkaloids react with p-toluene sulphonyl chloride to form the

corresponding sulphonamide derivatives as precipitate, the enol form of
which have acidic α-OH groups are soluble in fixed alkali.

• Secondary alkaloids, on the other hand, react in a similar manner to form
the corresponding sulphonamide derivatives which have no α-OH functions

and therefore are insoluble in fixed alkali.

• Tertiary alkaloids do not react .

Mixture of 1ry ,2ry and 3ry alkaloids

p-toluene sulphonyl chloride / Filter

ppt. filtrate
……………. ………

NaOH

ppt. filtrate
………….. ……………

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