反应详情

15 g of crude (±)-1-amino-4-hydroxymethyl-2-cyclopentene hydrochloride (prepared as described in J. Org. Chem. 1981, 46, 3268) were dissolved in a mixture of 150 ml of water and 150 ml of dioxane at room temperature under nitrogen. The solution was adjusted to pH 14 with 1N NaOH, then a diethyl ether solution of tert-butyloxycarbonyl fluoride (BOC-F, 20% excess) was added, and the mixture was stirred for a further 3 h at room temperature (BOC-F prepared as disclosed in Synthesis 1975, 599). The pH was adjusted to 2 with conc. HCl. After distillation of the organic solvents, 50 ml of water were added to the residue, and the mixture was extracted with 3×100 ml of ethyl acetate. The combined organic phases were completely evaporated. The residue was crystallized in a mixture of 110 ml of diisopropyl ether and 80 ml of n-hexane. 11.95 g of title compound were obtained. The yield was 56%.

1. distillationAfter distillation of the organic solvents, 50 ml of water
2. additionwere added to the residue
3. extractionthe mixture was extracted with 3×100 ml of ethyl acetate
4. customThe combined organic phases were completely evaporated
5. customThe residue was crystallized in a mixture of 110 ml of diisopropyl ether and 80 ml of n-hexane