反应详情

A solution of 1-(4-methoxybenzyl)tetrazole (6.12 g; Y. Satoh and N. Marcopulos, Tetrahedron Letters, 1995, 36, 1759-1762), and N,N,N'N'-tetramethylethylenediamine (10 ml) in dry tetrahydrofuran (10 ml) under nitrogen was cooled to -95° C. and treated dropwise with n-butyl lithium (2.5 M solution in hexanes) over 15 minutes. The reaction mixture was left at -80° C. for 15 minutes when 2-chlorobenzaldehyde (4.53 g) was added dropwise over 10 minutes maintaining the reaction temperature at or below -80° C. The mixture was stirred at or below -80° C. for 30 minutes, allowed to warm to room temperature, quenched with ammonium chloride solution (50 ml) and the organic phase separated. The aqueous phase was extracted three times with ethyl acetate (50 ml), the combined organics dried over magnesium sulphate and evaporated. The residue was purified by flash chromatography on silica eluting initially with a mixture of ethyl acetate and pentane (1:1, v/v) then with a mixture of ethyl acetate and pentane (2:1, v/v). Fractions homogenous in the required product were combined and evaporated affording the title compound (1.33 g) as a white solid, m.p. 128-130° C. [Elemental analysis:-C,58.22; H,4.74; N,17.15%. Calculated:-C,58.1; H,4.57; N,16.94%].

1. additionwas added dropwise over 10 minutes
2. temperaturemaintaining the reaction temperature at or below -80° C
3. customquenched with ammonium chloride solution (50 ml)
4. customthe organic phase separated
5. extractionThe aqueous phase was extracted three times with ethyl acetate (50 ml)
6. dry with materialthe combined organics dried over magnesium sulphate
7. customevaporated
8. customThe residue was purified by flash chromatography on silica eluting initially with a mixture of ethyl acetate and pentane (1:1
9. additionv/v) then with a mixture of ethyl acetate and pentane (2:1
10. customevaporated