الفهرس 
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Abstract
SUMMARY
SOME REACTIONS WITH 1-PHENYL-4-
SUBSTITUTED PYRAZOLO [3,4-d]
PYRIMIDINE.
In VJew of the varied physiological activities of
pyrimidine derivatives, the present investigation concerns with
synthesis of some new pyrimidine derivatives as antimicrobial
agents using 4-hydroxy-l-phenylpyrazolo[3,4-d]pyrimidine
(la), 4-chloro-l-phenylpyrazolo[3,4-d]pyrimidine (lb) and 4-
hydrazino-l-phenylpyrazolo[3,4-d]pyrimidine (lc) as starting
materials.
Electrophilic alkylation of 4-hydroxy-1-phenylpyrazolo
[3,4-d]pyrimidine (la) with formaldehyde in the presence of
amides or imides afforded the corresponding Mannich bases
(2), (3) and (4). Furthermore, alkylation of! a using dimethyl
sulphate and ethyl chloroacetate led to the formation of the
corresponding N-alkylated products (5 a, b), while benzoylation
of I a with benzoyl chloride gave 5 c.
Treatment of 5b with hydrazine hydrate afforded 5d
which underwent condensation on heating with phenyl
isothiocyanate giving thiosemicarbazide derivative (5e). Also,
5d reacted with acetylacetone, P-chlorobenzaldehyde and
different acids to produce the corresponding pyrazolopyrimidine
derivatives (6), (7) and (8). Compound 5e when
cyclized in presence of sodimn hydroxide, phosphoric acid and
Iz in KI furnished targetted triazole derivative (9), thiadiazole
derivative (10) and oxadiazole derivative (11), respectively.