Abstract
A series of newly substituted thieno[3,2-g]chromene derivatives were synthesized from 1-(7-mercapto-2,2-dimethylchroman-6-yl)ethanone (3) as starting material. The compound 3 in turn was synthesized by reacting of 1-(2,4-dihydroxyphenyl)ethanone with isoprene to get compound 2 followed by its reaction with phosphorus pentasulfide. Condensation of 3 with N-phenylchloroacetamide or phenacylbromide gave the corresponding thienochromene derivatives 5 and 6. Also, compound 3 was reacted with maleic anhydride and acrylonitrile to afford the corresponding derivatives 8 and 9, respectively. Alkylation of 3 with diazomethane or ethyl bromoacetate afforded the corresponding S-substituted derivatives 10 and 11. The latter compound 11 was cyclized to ester derivative 12, which was obtained directly from 3 on reaction with ethyl bromoacetate. Treatment of 12 with hydrazine hydrate afforded the corresponding hydrazide 13, which was condensed with aromatic aldehydes or acetyl acetone to yield the corresponding Schiff's bases 14a-d S-pyrazolo derivative 15, respectively. Finally, compound 13 was treated with 2,5-hexandione or carbon disulfide to give the corresponding compounds 16 and 17, respectively. Some of the newly synthesized compounds exhibited better anti-inflammatory activities than the reference controls with low concentrations. The structures of newly synthesized compounds were confirmed by chemical, elemental, and spectroscopic evidences. The detailed synthesis, spectroscopic data, and pharmacological activities were reported.