P. Shanmugam

Synthese von 4-Methylfuro[2,3-b]chinolin und Analogen Furochinoline, 5. Mitt

Synthesen von4-Methylfuro[2,3-b]chinolin und seinen Analogen, ausgehend von den entsprechenden 3-Vinyl-2-chinolonen, werden beschrieben.

Furochinoline, 9. Mitt.: Synthese von Furo[2,3-b]chinolinen

The synthesis of a wide variety of furo[2,3-b]quinolines starting from substituted 3-vinyl-2-quinolones is described. The procedure involves acetoxycyclisation of the vinyl-quinolone by treating with iodine in the presence of silver acetate and dehydroacetoxylation of the resulting 3-acetoxy-2,3-dihydrofuro[2,3-b]quinoline with phosphoric or polyphosphoric acid. The NMR spectra of the furoquinolines are discussed.

Synthese von Furo [2,3-b]chinolinen

A new route to furo[2,3-b]quinolines has been developed based on the use of N-arylaconamides as starting materials. These anilides when heated with polyphosphoric acid, readily underwent intramolecular cyclization to furnish the respective 1,2-dihydro-2-oxo-quinoline-3-acetic acids which were then transformed into the corresponding dihydrofuro[2,3-b]quinolines by literature procedures. Sequential treatment of the dihydro compound withNBS andDBU afforded the corresponding furo[2,3-b]quinoline. The NMR spectra of the furoquinolines are discussed.

Thienoquinolines. Part 6. Reaction of 2-chloro-3-(1,2-dibromoethyl)-quinolines with thiourea: a convenient synthesis of thieno[2,3-b]-quinolines

The reactions of 2-chloro-3-(1,2-dibromoethyl)quinolines (2) with thiourea in protic solvents affords thieno-[2,3-b]quinolines (3) in high yields.