Cl.[NH2:2][C@H:3]1[CH2:8][CH2:7][C@H:6]([C:9]([O:11][CH3:12])=[O:10])[CH2:5][CH2:4]1.C(N(CC)CC)C.Cl[C:21]([O:23][CH2:24][CH2:25][Cl:26])=[O:22].Cl>C(Cl)(Cl)Cl>[Cl:26][CH2:25][CH2:24][O:23][C:21]([NH:2][C@H:3]1[CH2:4][CH2:5][C@H:6]([C:9]([O:11][CH3:12])=[O:10])[CH2:7][CH2:8]1)=[O:22]Methyl trans-4-aminocyclohexanecarboxylate hydrochloride (5.00 g) obtained in Reference Example 2(1) is dissolved in chloroform (60 ml), and thereto is added triethylamine (11 ml) under ice-cooling, followed by dropwise addition of a solution of 2-chloroethyl chloroformate (3.3 ml) in chloroform (10 ml). After stirring at room temperature for 2.5 hours, to the reaction solution is added 5% hydrochloric acid and the mixture is extracted with chloroform. The organic layer is washed with saturated brine, dried over sodium sulfate, and then evaporated to remove the solvent under reduced pressure. The resulting residue is suspended in chloroform/diisopropyl ether. The precipitates are collected by filtration and dried to give methyl trans-4-{[(2-chloroethoxy)carbonyl]amino}cyclohexanecarboxylate (5.11 g).
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