反应详情

To a solution (“soln.”) of 6-aminohexanoic acid (1; 144 mg, 1.1 mmol) in 9% aq. Na2CO3 soln. (2.4 ml) was added a soln. of (9H-fluoren-9-yl)methyl succinimidyl carbonate (2; 337 mg, 1 mmol) in DMF (2.5 ml). After stirring for 1 h at room temperature (“r.t.”), the mixture was diluted with H2O (50 ml) and extracted twice with Et2O (2×20 ml). Then, the H2O phase was acified with conc. HCl soln. to pH 2 and extracted with AcOEt (5×30 ml). The organic (“org.”) layer was dried (MgSO4) and evaporated. The residue was crystallized in CHCl3/petroleum ether: 306 mg (86%) of 3. Colorless crystals. M.p. 116°. 1H-NMR (CDCl3): 7.80-7.55 (2m, H—C(1)(fmoc), H—C(4)(fmoc), H—C(5)fmoc, H—C(8)(fmoc); 7.45-7.25 (m, H—C(2)(fmoc), H—C(3)(fmoc), H—C(6)(fmoc), H—C(7)(fmoc); 4.45 (m, CH2O)(fmoc)); 4.2(m, H—C(9)(fmoc)); 3.25-3.0, 2.4, 1.8-1.3 (3m, NH(CH2)5CO). Anal. calc. for C21H23NO4 (353.42): C 71.37, H 6.56, N 3.96; found: C 71.35, H 6.65, N 3.93.

1. addition(2.4 ml) was added a soln
2. extractionextracted twice with Et2O (2×20 ml)
3. extractionto pH 2 and extracted with AcOEt (5×30 ml)
4. dry with materialThe organic (“org.”) layer was dried (MgSO4)
5. customevaporated
6. customThe residue was crystallized in CHCl3/petroleum ether