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DOI: 10.1055/s-0029-1216894
One-Pot Synthesis of Furo[3,4-b]pyridin-5(7H)-ones from 2-Bromopyridine-3-carboxylic Acid and Carbonyl Compounds
Publikationsverlauf
Publikationsdatum:
10. Juli 2009 (online)
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Abstract
A one-pot method for the preparation of furo[3,4-b]pyridine-5(7H)-ones from commercially available 2-bromopyridine-3-carboxylic acid has been developed. Thus, this acid is treated with two molar amounts of butyllithium to generate lithium 2-lithiopyridine-3-carboxylate, which is then allowed to react with carbonyl compounds to afford, after treatment with hydrochloric acid, the desired furopyridinones in reasonable yields.
Key words
furopyridinones - 2-bromopyridine-3-carboxylic acid - lithium 2-lithiopyridine-3-carboxylate - bromine-lithium exchange - lactonization
- Generation of lithium 2-lithiobenzoate from 2-bromoben-zoic acid has been reported by Parham et al.:
-
1a
Parham WE.Piccirilli RM. J. Org. Chem. 1976, 41: 1268 - Its applications to the synthesis of phthalides have also been reported:
-
1b
Parham WE.Egberg DC.Sayed YA.Thrrailkill RW.Kaeyser GE.Neu M.Montgomery WC.Jones LD. J. Org. Chem. 1976, 41: 2628 -
1c
Pirkle WH.Sowin TJ. J. Org. Chem. 1987, 52: 3011 -
2a
Canonne P.Lemay G.Belanger D. Tetrahedron Lett. 1980, 21: 4167 -
2b
Kende AS.Veits JE.Lorah DP.Ebetino FH. Tetrahedron Lett. 1984, 25: 2423 -
2c
van Bergman TJ.Kellogg RM. J. Am. Chem. Soc. 1972, 94: 8451
References
When the treatment of 1 with n-BuLi was prolonged to 10 min, only trace amounts of the desired products were obtained. The stability of this dilithium intermediate 2 could not be improved by using Et2O or DME in place of THF.