| abstract |
Pyrazolo[1,5-a]pyrimidine derivatives having an analgetic action, thus being useful as an analgetic, and represented by general formula (1), wherein R1 represents lower alkyl, lower alkenyl, hydroxy-(lower) alkyl, lower alkylthi o (lower) alkyl, lower alkanoyloxy (lower) alkyl, lower alkoxy (lower) alkyl, furyl or thienyl; R2 represents pyridyl, 1-oxydopyridyl, lower alkyl- substituted pyrazinyl, lower alkyl-substituted pyrimidinyl or phenyl optionally having one to three substituents selected from among lower alkyl, lower alkoxy and halogeno; R3 represents hydrogen or halogeno; and A represents a single bond or lower alkylene, provided that when R1 is lower alkyl, then R2 is lower alkyl-substituted pyrazinyl or lower alkyl-substitut ed pyrimidinyl. |