FOERFARANDE FOER FRAMSTAELLNING AV 5-PYRIDYLETENYLDERIVAT AV 1H-PYRAZOLO/1,5-A/PYRIMIDINER

Compounds of the formula (I) (I) wherein R1 is: (a) hydrogen, or C1-C6 alkyl; (b) an unsubstituted 2-pyridyl or 3-pyridyl group; (c) a benzyl group, wherein the phenyl ring is unsubstituted or substituted by halogen, C1-C6 alkoxy or C1-C6 alkyl; (d) a phenyl ring, unsubstituted or substituted by one or two groups chosen from halogen, trihalomethyl, C1-C6 alkoxy, C1-C6 alkyl, C2-C6 alkanoylamino, nitro and amino; each of R2 and R3 independently represents hydrogen, halogen or C1-C6 alkyl; R4 represents a 2-pyridyl, 3-pyridyl or 4-pyridyl group, unsubstituted or substituted by C1-C6 alkyl; and the pharmaceutically acceptable salts thereof are disclosed. The compounds have activity in the gastroenteric system, particularly anti-ulcerogenic and gastric anti-secretory activity. Additionally, the compounds have activity in reducing the undesired gastrointestinal side-effects resulting from systemic administration of anti-inflammatory prostaglandin synthetase inhibitors.