Abstract:
This research was carried out to obtain a convenient route for the
synthesis of [7_ 14C]-p-hydroxy benzaldehyde.
Section 1 of the thesis includes a route involving intermediates with
protecting groups like benzyl and methyl ethers of the phenols. The
benzyl ethers afforded the product in relatively better yield. The overall
synthesis involves four steps.
Section 2 describes the reactions carried out directly on phenols,
and a three step pathway is obtained for the synthesis of p-hydroxy
benzaldehyde, which was repeated on labelled compounds to obtain [7_14C]p-
hydroxy benzaldehyde. The synthesis involves the reaction of p-bromophenol
with Cu14CN to yield [7_ 14C]-p-cyano phenol, which is then reduced
to the aldehyde by means of a simple and clean photolysis method.
The same route was tried out to get 3,4-dihydroxybenzaldehyde
and was found to work equally well for the synthesis of this compound.
Section 3 deals with the isolation of labelled alkaloids, corydaline,
protopine and reticu1ine from [2-3H,1-14C]-dopamine (3H/ 14C ratio = 4)
fed Corydalis solida. 3H/14C ratios in the labelled alkaloids were
determined. The uncorrected values showed almost 50% loss of 3H relative
to 14C in reticuline, and roughly 75% loss of the 3H relative to 14C
in corydaline and protopine.
