C[N:2]1[CH2:7]COCC1.ClC(OCC)=[O:10].[C:14]([CH2:16][CH2:17][O:18][C:19]([CH2:21][C:22]1([CH2:28]C(O)=O)[CH2:27][CH2:26][CH2:25][CH2:24][CH2:23]1)=[O:20])#[N:15].[N-]=[N+]=[N-].[Na+]>C1COCC1>[N:2]([CH2:28][C:22]1([CH2:21][C:19]([O:18][CH2:17][CH2:16][C:14]#[N:15])=[O:20])[CH2:23][CH2:24][CH2:25][CH2:26][CH2:27]1)=[C:7]=[O:10]
1.5 mL of N-methyl morpholine (13.62 mmol) and 1.3 mL of ethyl chloroformate (13.03 mmol) was added to a solution of 1-[(2-cyanoethoxycarbonyl)-methyl]-1-cyclohexane acetic acid (5) (11.84 mmol) in 30 mL of anhydrous THF at −20° C. under nitrogen atmosphere. The reaction mixture was stirred at −20° C. for 20 minutes, warmed to −5° C., an aqueous solution of NaN3 (29.61 mmol, in 3.5 mL of H2O) was added and then stirred for 30 minutes at −5° C. to −10° C. Then, THF was removed under reduced pressure and the residue was extracted with CH2Cl2 and dried over Na2SO4. After concentration in vacuo the crude product was dissolved in 20 mL of anhydrous toluene and refluxed for 20 minutes. The mixture was cooled to room temperature and toluene was removed under reduced pressure. The residue was purified on silica gel (15% ethyl acetate in hexane) to afford 1.9 g (64%) of the title compound. 1H NMR (CDCl3): δ 4.29 (2H, t, J=6.0 Hz); 3.42 (2H, s); 2.73 (2H, t, J=6.0 Hz); 2.44 (2H, s); 1.49-1.39 (10H, m).
Loading…
