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Seven new phthalimide derivatives (9a-g) with 1,2,4-oxadiazol-5-yl methyl group attached to nitrogen have been synthesized from N-phthaloylglycine 6 and arylamidoximes 7a-g. All of these showed potent analgesic effect with acetic acid induced "writhing" test in mice. One of the better compounds (ID50 = 2.2 mg/Kg i.p.) has been found to be 9a which also demonstrates analgesic activity against inflammatory pain.

Significant local analgesic and anti-inflammatory activity has been observed after oral administration of 3-[3-(phenyl)-1,2,4-oxadiazol-5-yl] propionic acid (POPA). Doses of 150 and 300 mg/kg body weight administered orally by gavage to adult (25-35 g) albino mice of both sexes can inhibit acetic acid-induced writhing by 31.0% and 49.5%, respectively (mean +/- SEM writhing numbers during 20 min were 52.0 +/- 6.0 and 38.3 +/- 7.2 vs 75.8 +/- 6.6 for control group which received saline; N = 6). Carrageenin-induced inflammation in the female Wistar rat (200-250 g) can be reduced by 43.3% and 42.2% 3 h after oral administration (gavage) of 75 and 150 mg/kg of POPA (mean +/- SEM, 30.0 +/- 1.3% and 30.6 +/- 2.4% vs 52.9 +/- 3.7% for control group which received saline; N = 5). In the hot plate test on adult albino mice (25-35 g) of both sexes, POPA (150 and 300 mg/kg, po) was totally ineffective (N = 10). Our results indicate that POPA appears to offer potential safety and efficacy as a local analgesic and anti-inflammatory agent with no central nervous system involvement

The Diels-Alder product from the reaction of methyl 2,3,6-trideoxy-alpha-D-glycero-hex-2-enopyranosid-4-ulose (1b) with trans-1-methoxy-3-tert-butyl-dimethylsilyloxy-1,3-butadiene is 3b (93%). Reaction of 3b wih sodium borohydride causes reduction of the C-4 carbonyl group only, but, with lithium aluminum hydride, further reactions occur which can be rationalized by fragmentation brought about by hydride cleavage on the silicon-oxygen bond, with simultaneous ejection of the beta-methoxyl group complexed to a trivalent aluminum species. The enone resulting from this fragmentation also reacts further with lithium aluminum hydride, and several products result. The behavior of postulated intermediates, which have been prepared separately and subjected to the reaction conditions, supports the proposed reaction mechanisms. The "second generation" enone (methyl 2,3,6-trideoxy-alpha-D-talopyranosido)-[3,2-d]-2-cyclohexenone+ ++ (10a), arising from the first generation precursors 1b, has been prepare by two routes.