反応 #338186

反応方程式

4-aminobutyraldehyde dimethyl acetal

1,1′-carbonyldiimidazole

DIPEA

benzyloxyamine hydrochloride

→

3-(4,4-dimethoxy-butyl)-1-(benzyloxy)-urea

収率 74.1%

溶媒

THF

反応条件

後処理

1. 1
   濃縮The mixture was concentrated under reduced pressure
2. 2
   workup.DISSOLUTIONthe residue was dissolved in DMF (50 mL)
3. 3
   濃縮then concentrated under reduced pressure
4. 4
   workup.DISSOLUTIONThe residue was dissolved in EtOAc (200 mL)
5. 5
   洗浄the solution was washed with brine (5×25 mL)
6. 6
   乾燥dried (MgSO4)
7. 7
   濃縮concentrated
8. 8
   その他Purification of the crude material by column chromatography on silica gel (4:1 hexanes-EtOAc followed by 100% EtOAc)

実験手順

To a solution of 4-aminobutyraldehyde dimethyl acetal (2.73 g, 20.5 mmol) in THF (50 mL) was added 1,1′-carbonyldiimidazole (3.39 g, 20.9 mmol) and the resultant mixture was stirred at room temperature for 45 minutes. The mixture was concentrated under reduced pressure and the residue was dissolved in DMF (50 mL) and treated with DIPEA (18 mL, 103 mmol) and benzyloxyamine hydrochloride (10.2 g, 64.0 mmol). The mixture was heated at 60° C. overnight then concentrated under reduced pressure. The residue was dissolved in EtOAc (200 mL) and the solution was washed with brine (5×25 mL), dried (MgSO4), and concentrated. Purification of the crude material by column chromatography on silica gel (4:1 hexanes-EtOAc followed by 100% EtOAc) provided 4.29 g (73%) of 3-(4,4-dimethoxy-butyl)-1-(benzyloxy)-urea as a yellow oil.

出典