Trifluoromethanesulfonate → HCID 131721502, compound

Temperature

-78 °C

A solution of (tetrahydrofuran-2-yl)tri-n-butylstannane (J. S. Sawyer, A. Kucerovy, T. L. MacDonald, and G. J. McGarvey, J. Amer. Chem. Soc., 1988, 110, 842) (3.0 g, 8.30 mmol) in THF (20 ml) was cooled to -78° C. n-Butyl lithium (6.23 ml of a 1.6M solution in hexane, 9.97 mmol) was then added and the solution was stirred for 15 min. at -78° C. A second flask containing copper (I) bromide.dimethylsulphide complex (0.854 g, 4.14 mmol) suspended in a mixture of dimethyl sulphide (15 ml) and THF (30 ml) was then cooled to -78° C. The α-lithiotetrahydrofuran species was transferred via a cannula to the suspension of copper bromide at -78° C. The red-brown homogeneous solution was stirred for 30 min. at -78° C. A third flask containing a solution of diphenylmethyl 7-phenylacetamido-3-triflyloxyceph-3-em-4-carboxylate (V. Farina, S. R. Baker, and S. I. Hanck, J. Org. Chem., 1989, 54, 4962) (1.9 g, 3.0 mmol) in a mixture of N-methylpyrrolidinone (20 ml) and THF (50 ml) was then cooled to -18° C. The cuprate species was transferred via a cannula to the solution of triflate at -78° C. The reaction mixture was stirred for 1 h at -78° C. then quenched by the addition of saturated aq. ammonium chloride (30 ml). The resulting mixture was allowed to warm to room temperature then diluted with water (100 ml) and extracted with ethyl acetate (100 ml, 30 ml). The combined organic phases were washed with water, brine, then dried over magnesium sulphate. After removal of the solvents under reduced pressure the crude reaction product was purified by flash chromatography on silica gel using 10-30% ethyl acetate/methylene dichloride as eluent. After elution of the 3-n-butylcephem, the title compound was obtained as a mixture of diastereoisomers of the Δ2 and Δ3 cephems (1.014 g, 61%).

1. additionwas then added
2. temperaturewas then cooled to -78° C
3. stirringThe red-brown homogeneous solution was stirred for 30 min. at -78° C
4. temperaturewas then cooled to -18° C
5. stirringThe reaction mixture was stirred for 1 h at -78° C.
6. customthen quenched by the addition of saturated aq. ammonium chloride (30 ml)
7. temperatureto warm to room temperature
8. additionthen diluted with water (100 ml)
9. extractionextracted with ethyl acetate (100 ml, 30 ml)
10. washThe combined organic phases were washed with water, brine
11. dry with materialdried over magnesium sulphate
12. customAfter removal of the solvents under reduced pressure the crude
13. customreaction product
14. customwas purified by flash chromatography on silica gel using 10-30% ethyl acetate/methylene dichloride as eluent
15. washAfter elution of the 3-n-butylcephem

ORD record

ord-b36b0387bbc4453e8de80446e20dc5ec

Source dataset

uspto-grants-2000_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06077952