3- (Nitrobenzylidene) -2,4 (3H,5H) -furandione in the Hantzsch-pyridine synthesis 2. 6,7-Dihydrophthalide

Görlitzer, K.; Bartke, U.

Die Pharmazie 57(10): 679-681

2002


ISSN/ISBN: 0031-7144
PMID: 12426947
Document Number: 550416
Melting the 3-(o- and p-nitrobenzylidene)tetronic acids 2a and 2c with the enaminocarbonyl compounds 1 at 70-90 degrees C yields the hexahydro-7a-hydroxyfuro[3,4-b]-pyridines 3, while with the m-nitro compound 2b at 100 degrees C the 6,7-dihydrophthalides 4 are obtained. Dehydrogenation of the dihydro derivatives 4 with activated manganese dioxide affords the phthalides 5.

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