Lithium Hydroxide → 5-Bromo-2-(3-tert-butoxycarbonyl-propoxy)-4-chloro-benzoic acid
反応式
C(OC(CCC[O:11][C:12](=[O:32])[C:13]1[CH:18]=[C:17]([Br:19])[C:16]([Cl:20])=[CH:15][C:14]=1[O:21][CH2:22][CH2:23][CH2:24][C:25]([O:27][C:28]([CH3:31])([CH3:30])[CH3:29])=[O:26])=O)(C)(C)C.[Li+].[OH-].OS([O-])(=O)=O.[Na+]>C1COCC1>[Br:19][C:17]1[C:16]([Cl:20])=[CH:15][C:14]([O:21][CH2:22][CH2:23][CH2:24][C:25]([O:27][C:28]([CH3:30])([CH3:29])[CH3:31])=[O:26])=[C:13]([CH:18]=1)[C:12]([OH:32])=[O:11]参加物
5
実験手順
A mixture of 5-bromo-2-(3-tert-butoxycarbonyl-propoxy)-4-chloro-benzoic acid 3-tert-butoxycarbonyl-propyl ester (8.2 g, 15.3 mmol) and LiOH (19.1 mL, 4 N, 76.6 mmol) in THF (150 mL) was stirred at rt for 16 hrs. The mixture was acidified by saturated NaHSO4 (50 mL) and extracted with ethyl acetate. The ethyl acetate layer was dried over Na2SO4, filtered and concentrated. The residue was purified via silica gel flash chromatography (eluting with 50% ethyl acetate in hexane), followed by crystallization in hexane/ethyl acetate (10/1) to afford 5-bromo-2-(3-tert-butoxycarbonyl-propoxy)-4-chloro-benzoic acid as white crystals (2.5 g). MS [M−(iso-butene+OH)]+: 320.8; tR=2.38 min. (method 1)
後処理
- extractionextracted with ethyl acetate
- dry with materialThe ethyl acetate layer was dried over Na2SO4
- filtrationfiltered
- concentrationconcentrated
- customThe residue was purified via silica gel flash chromatography (eluting with 50% ethyl acetate in hexane)
- customfollowed by crystallization in hexane/ethyl acetate (10/1)
出典と根拠
- ORDレコード
- ord-00f41868b7da46239da67db3dccc7990
- 出典データセット
- uspto-grants-2011_12
- 特許番号
- US08084614B2
反応ノート
読み込み中…