Synthesis of azuleno [1, 2-b]-and azuleno [1, 2-c] thiophenes by the reactions of 2H-cyclohepta [b] furan-2-ones with enamines of 3-oxotetrahydrothiophenes
New heterocyclic compounds, azuleno [1, 2-b]-and azuleno [1, 2-c] thiophene, are synthesized by the reaction of 3-methoxycarbonyl-2H-cyclohepta [b] furan-2-one with morpholino enamines of 3-oxotetrahydrothiophene, followed by dehydrogenation of resulting dihydrocompounds with 2, 3-dichloro-5, 6-dicyano-p-benzoquinone.
![2-Methyl-1,2-dihydro-3-thia-cyclopenta[a]azulene-9-carboxylic acid methyl ester结构式](https://image.chemsrc.com/caspic/318/88498-73-1.png)
![methyl 2-methylazuleno[1,2-b]thiophene-4-carboxylate结构式](https://image.chemsrc.com/caspic/166/88498-77-5.png)
![3-(甲氧羰基)-2H-环庚[b]呋喃-2-酮结构式](https://image.chemsrc.com/caspic/021/50603-71-9.png)
![methyl 1,3-dihydroazuleno[1,2-c]thiophene-9-carboxylate结构式](https://image.chemsrc.com/caspic/280/88498-74-2.png)
![methyl azuleno[1,2-c]thiophene-9-carboxylate结构式](https://image.chemsrc.com/caspic/128/88498-78-6.png)
![2-methylazuleno[1,2-b]thiophene结构式](https://image.chemsrc.com/caspic/090/88498-79-7.png)
![methyl 2,3-dihydroazuleno[1,2-b]thiophene-4-carboxylate结构式](https://image.chemsrc.com/caspic/356/88498-72-0.png)
![methyl azuleno[1,2-b]thiophene-4-carboxylate结构式](https://image.chemsrc.com/caspic/204/88498-76-4.png)