反应详情

To a solution of 1-methyltetrazole (2.9 g, 34.7 mmol) and TMEDA (10 ml, 66.2 mmol) in THF (100 ml) cooled at −78° C. is added dropwise 2.5 M nBuLi in hexanes (13.9 ml, 34.7 mmol) with vigorous stirring and maintaining the reaction temperature below −65° C. On complete addition, the mixture is is stirred 20 minutes before adding dropwise a solution of N-methyl-N-methoxy-(3-methylpyridin-2-yl)carboxamide (6.3 g, 34.7 mmol) in THF. On complete addition, the mixture is stirred for six hours at −78° C. before adding slowly a half-diluted saturated aqueous NaHCO3 solution (300 ml). The mixture is extracted with ethyl acetate (500 ml). After separation, the organic layer is dried (MgSO4), filtered and concentrated. Silica-gel chromatography of the residue affords 2.8 g of (3-methylpyridin-2-yl)-(1-methyltetrazol-5-yl)methanone [yield 39.7%; 1H-NMR (DMSO-d6) δppm: 2.6 (s, 3H), 4.17 (s, 3H), 7.65 (dd, 1H), 7.95 (d, 1H), 8.56 (d, 1H)].

1. temperaturemaintaining the reaction temperature below −65° C
2. additionOn complete addition
3. stirringthe mixture is is stirred 20 minutes
4. additionOn complete addition
5. stirringthe mixture is stirred for six hours at −78° C.
6. extractionThe mixture is extracted with ethyl acetate (500 ml)
7. customAfter separation
8. dry with materialthe organic layer is dried (MgSO4)
9. filtrationfiltered
10. concentrationconcentrated