反应详情

Under N2, a solution of ethyl 2-chloroacetoacetate (1.8 ml, d=1.15, 0.013 mol) in CHCl3 (50 ml) was added dropwise to a solution 4-methoxybenzamidine (3.9 g, 0.026 mol) in CHCl3 (100 ml). After stirring overnight, the reaction mixture was filtered and the filtrate was washed with dilute NaOH solution. The aqueous layer was extracted with CH2Cl2 (3×) and the organic layer was dried, filtered and concentrated to dryness. The residue was chromatographed on silica gel and the product was eluted with 2% CH3OH-CHCl3 (v/v) to yield 0.7 g (22%) of product m.p. 250°-251° C.

1. filtrationthe reaction mixture was filtered
2. washthe filtrate was washed with dilute NaOH solution
3. extractionThe aqueous layer was extracted with CH2Cl2 (3×)
4. customthe organic layer was dried
5. filtrationfiltered
6. concentrationconcentrated to dryness
7. customThe residue was chromatographed on silica gel
8. washthe product was eluted with 2% CH3OH-CHCl3 (v/v)