反応 #48400

反応方程式

HCl

benzyl N2,N2-bis(tert-butoxycarbonyl)-5-(2,3-dichlorophenyl)-D-lysinate

NaOH

triethylamine

NaHCO3

EDC

HOAT

→

di-tert-butyl [(3R)-6-(2,3-dichlorophenyl)-2-oxoazepan-3-yl]imidodicarbonate

収率 82.3%

溶媒

MeOH

water

DCM

反応条件

後処理

1. 1
   濃縮concentrated
2. 2
   その他the layers separated
3. 3
   乾燥The combined organics were dried over magnesium sulfate
4. 4
   ろ過filtered
5. 5
   濃縮concentrated
6. 6
   その他This residue was purified by silica gel chromatography (0.5%→10% MeOH/DCM)

実験手順

To a solution benzyl N2,N2-bis(tert-butoxycarbonyl)-5-(2,3-dichlorophenyl)-D-lysinate (0.45 g, 0.77 mmol) in MeOH (4 mL) and water (2 mL) was added 1N NaOH (3.1 mL, 3.1 mmol). This solution was heated to 40° C. for 6 h, then neutralized with 1N HCl and concentrated. To a solution of this residue in DCM (10 mL) were added EDC (0.19 g, 0.97 mmol) and HOAT (53 mg, 0.39 mmol) followed by triethylamine (0.32 mL, 0.73 mmol). After 2 h, NaHCO3 was added, the layers separated and the aqueous phase backwashed with DCM. The combined organics were dried over magnesium sulfate, filtered and concentrated. This residue was purified by silica gel chromatography (0.5%→10% MeOH/DCM) to give di-tert-butyl [(3R)-6-(2,3-dichlorophenyl)-2-oxoazepan-3-yl]imidodicarbonate (300 mg). MS 473 (M+1). Standard deprotection of a portion of this material gave the title product. MS 273 (M+1).

出典