Preparation of highly functionalized pyridylmagnesium reagents for the synthesis of polyfunctional pyridines

Synlett

Volumn , Issue 12, 1998, Pages 1359-1360

  Bérillon, Laurent ^a   Leprêtre, Anne ^b   Turck, Alain ^b   Plé, Nelly ^b   Quéguiner, Guy ^b   Cahiez, Gérard ^c   Knochel, Paul ^a  

^a PHILIPPS UNIVERSITY MARBURG   (Germany)

^b CNRS   (France)

^c 5 Mail Gay Lussac   (France)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0002836067     PISSN: 09365214     EISSN: None     Source Type: Journal    
DOI: 10.1055/s-1998-17871     Document Type: Article

References (10)

1. Quéguiner, G.; Marsais, F.; Snieckus, V.; Epsztajn, J. Adv. Heterocycl. Chem. 1992, 52, 187.
2. Trécourt, F.; Gervais, B.; Mallet, M.; Quéguiner, G. J. Org. Chem. 1996, 61, 1673.
3. Mongin, F.; Mongin, O.; Trécourt, F.; Godard, A.; Quéguiner, G. Tetrahedron Lett. 1996, 37, 6695.
4. Cochennec, C.; Rocca, P.; Marsais, F.; Godard, A.; Quéguiner, G. Synthesis 1995, 321.
5. Boymond, L.; Rottländer, M.; Cahiez, G.; Knochel, P. Angew. Chem., Int. Ed. Engl. 1998, 37, 1701.
6. For the performance of an iodine-magnesium exchange on unfunctionalized pyridines, see: Furukawa, N.; Shibutani, T.; Fujihara, H. Tetrahedron Lett. 1987, 28, 5845.
7. Cox, J.M.; Ghosh, R. Tetrahedron Lett. 1969, 3351.
8. Kahne, D.; Collum, D.B. Tetrahedron Lett. 1981, 22, 5011.
9. Klement, I.; Lennick, K.; Tucker, C.E.; Knochel, P. Tetrahedron Lett. 1993, 34, 4623.
10. Topical procedure: preparation of 2-chloro-4-pyridyl(phenyl)methyl alcohol (3a): A dry three-necked flask equipped with a magnetic stirring bar, a thermometer and a septum was charged with 2-chloro-4-iodopyridine (1a: 718 mg, 3.0 mmol) in THF (7 mL) and cooled to -40°C. i-PrMgBr (4.34 mL, 3.3 mmol, 0.76 M in THF) was added dropwise and the reaction mixture was stirred at -40°C for 0.5 h. Benzaldehyde (477 mg, 4.5 mmol) was added and the reaction mixture was stirred for one hour at -40°C. The cooling bath was removed allowing the reaction temperature to rise to 0°C. The reaction mixture was quenched with brine (15 mL). After extraction with EtOAc, usual work-up and evaporation of the solvents the crude product was purified by chromatography (pentane:ether 1:1) yielding the pure desired product 3a (606 mg, 92% yield) as a yellow solid (mp = 93°C).