R. Sleziak, Slávka Balážiová, A. Krutošíková
1999
Citations
0
Influential Citations
13
Citations
Journal
Collection of Czechoslovak Chemical Communications
Abstract
The synthesis of methyl 2-formyl-6-(methoxymethyl)furo[2,3- b ]pyrrole-5-carboxylate ( 1d ) is described. The reactions of methyl 2-formylfuro[2,3- b ]pyrrole-5-carboxylates 1a - 1d with malononitrile afforded methyl 2-(2,2-dicyanovinyl)furo[2,3- b ]pyrrole-5-carboxylates 3a - 3d , with methyl cyanoacetate methyl 2-[2-cyano-2-(methoxycarbonyl)vinyl]furo[2,3- b ]pyrrole-5-carboxylates 4a - 4d and with 2-furylacetonitrile methyl 2-[2-cyano-2-(2-furyl)vinyl]furo[2,3- b ]pyrrole-5-carboxylates 5a - 5d . Compounds 1b - 1d and methyl azidoacetate gave the appropriate vinylazides 6b - 6d , which were used for preparation of substituted furo[2,3- b :4,5- b ']dipyrroles 7b - 7d . Reactivity of furo[2,3- b ]pyrrole aldehydes 1a - 1d and furo[3,2- b ]pyrrole aldehydes 2a - 2c in their reactions with 5,5-dimethylcyclohexane-1,3-dione is compared. The prepared methyl 2-[bis(4,4-dimethyl-2,6-dioxocyclohexyl)methylfuro[2,3- b ]pyrrole-5-carboxylates 8a - 8d and their isomers 10a - 10c cyclized into substituted octahydroxanthenes 9a - 9d and 11a - 11c , respectively. Methyl 4-benzyl-2- [(4,4-dimethyl-2,6-dioxocyclohex-1-ylidene)methyl]furo[3,2- b ]pyrrole-5-carboxylate ( 12 ) was prepared using microwave irradiations.