反応 #320520

ord-769171b329f44205846c3f76086df0b3

反応条件

詳細条件
See reaction.notes.procedure_details.

後処理

  1. 1
    温度warmed to 22°
  2. 2
    その他The phases were separated
  3. 3
    洗浄the organic phase was washed with saturated sodium chloride solution
  4. 4
    その他dried
  5. 5
    濃縮concentrated
  6. 6
    その他The residue was recrystallized from 40 ml of ethyl acetate and 160 ml of hexane
  7. 7
    その他the crystallizate was dried

実験手順

41.7 ml of a 2.6 molar solution of hexyllithium in hexane were added dropwise at -80° C. to a solution of 9.50 g of methyl (S)-2-methoxycarbonylamino-3-phenyl-propionate and 3.22 ml of bromochloromethane in 60 ml of tetrahydrofuran. Subsequently, a further 2.14 ml of bromochloromethane were added and the mixture was again treated with 23 ml of hexyllithium solution, a further 1.54 ml of bromochloromethane were added and the mixture was again treated with 7.7 ml of hexyllithium solution. The solution was treated at -80° C. with 15 ml of 20% methanolic hydrochloric acid, warmed to 22° and diluted with 100 ml of water and 40 ml of tetrahydrofuran. The phases were separated, the organic phase was washed with saturated sodium chloride solution, dried and concentrated. The residue was recrystallized from 40 ml of ethyl acetate and 160 ml of hexane and the crystallizate was dried, there being obtained 3.83 g (37%) of pure methyl (S)-(1-benzyl-3-chloro-2-oxo-propyl)-carbamate, m.p. 121°-122° C. IR (KBr): 3336s (NH), 1737s and 1686s (C=O), 1535s (amide II).

出典

DOI: 10.6084/m9.figshare.5104873.v1特許: US05591885uspto-grants-1997_01