Original Articles: 2010 Vol: 2 Issue: 6
Synthesis of urethanes and substituted ureas encompassing naphtho[2.1-b]furan and evaluation their analgesic activity
Ethyl naphtho[2,1-b]furan-2-carboxylate 1 was synthesized from 2-hydroxy-1-naphthaldehyde by reacting it with ethyl chloroacetate in presence of anhydrous potassium carbonate and dimethyl formamide. The ester 1 was converted to naphtho[2,1-b]furan-2-carboxyhydra zide 2 by treating it with hydrazine hydrate in alcohol. Nap htho[2,1-b]furan-2-carboxyazide 3 was obtained by reacting hydrazide 2 with nitrous acid at low temperature. The reaction of 3 with various alcohols, phenols and drugs- chloramphenico l, sulphathiazole and paracetamol resulted in the formation of new heterocyclic compounds, 2-s emicarbazidonaphtho[2,1-b]furans (4a- j) (urethanes and substituted urea) . The newly synthesized compounds were characterized by spectral methods and evaluated for analgesic activi ty by acetic acid induced writhing method and Eddy’s hot plate method by using Swiss mice. So me of he compounds exhibited considerable analgesic activity.