SYNTHESIS OF 5-ARYL-2-OXAZOLEPROPIONIC ACIDS AND ANALOGS . ANTIINFLAMMATORY AGENTS

Condensation of 2‐bromoacetophenones with sodium succinimide gave N‐phenacylsuccinimides (1) which were opened with sodium hydroxide to N‐phenacylsuccinamic acids (2). The latter were cyclized to 5‐aryl‐2‐oxazolepropionic acids (3) in sulfuric acid. Similar cyclization of N‐phenacylphthalamic acid (5) and succinic acid 2‐benzoylhydrazide (7) gave o‐(5‐phenyl‐2‐oxazolyl)benzoic acid (6) and 5‐phenyl‐1,3,4‐oxadiazole‐2‐propionic acid (8). The succinamic acids 2 and the phthalamic acid 5 were observed to recyclize to the corresponding imides (1 and 4) on heating, and the succinic acid hydrazide 7 was similarly cyclized to N‐benzamidosuccinimide (9) with acetic anhydride. Antiinflammatory screening data are reported for 3, 6 and 8. Copyright © 1969 Journal of Heterocyclic Chemistry