الفهرس | Only 14 pages are availabe for public view |
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. |