
TY  - JOUR
A1  - Huppatz, JL 
T1  - Systemic Fungicides. The Synthesis of Pyrazolo[1,5-<i>a</i>]pyrimidine Analogues of Carboxin
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1985
VL  - 38
IS  - 1
SP  - 221
EP  - 230
KW  - 
UR  - https://doi.org/10.1071/CH9850221 
N2  - The synthesis of a series of pyrazolo [1,5-a] pyrimidine derivatives, structural analogues of the systemic fungicide carboxin, is described. A common intermediate incorporating structural features desirable for fungicidal activity, N-phenyl-3(5)-amino-5(3)-methylpyrazole-4- carboxamide (6), was used to prepare pyrazolo [1,5-a] pyrimidines variously substituted in positions 5 and 7 of the ring system. Bromination of N-phenyl-2-methylpyrazolo[1,5-a]pyrimidine-3-carboxamide (8) occurred preferentially in the phenyl ring and the 6-bromo derivative was prepared by bromination of the corresponding 3-ethoxycarbonyl derivative (24). Attempted nitration of the ester (24) resulted in displacement of the ethoxycarbonyl substituent by a nitro group. The simplest pyrazolo [1,5-a] pyrimidine (8) showed a high level of fungicidal acitvity in fungal growth assays of Basidiomycete species, but compounds substituted in the pyrimidine ring were inactive. 
ER  -

