反応 #3361

反応方程式

2-[2-(1-carboxy-2-methylbutylcarbamoyl) phenyldisulfanylbenzoylamino]-3-methylpentanoic acid

bromine

→

title compound

3-Methyl-2-(3-oxo-3h-benzo[d]isothiazol-2-yl)pentanoic acid

溶媒

dichloromethane

反応条件

後処理

1. 1
   濃縮concentrated to dryness in vacuo
2. 2
   その他The residue was triturated with dichloromethane
3. 3
   その他The dichloromethane was removed by evaporation in vacuo
4. 4
   その他to remove excess bromine
5. 5
   その他The residue was partitioned between dichloromethane/5% aqueous sodium bicarbonate (200 mL each)
6. 6
   その他The aqueous layer was separated
7. 7
   洗浄washed with fresh dichloromethane
8. 8
   抽出The acidic aqueous solution was extracted with dichloromethane (2×75 mL)
9. 9
   洗浄washed with water
10. 10
    乾燥dried (MgSO4)
11. 11
    ろ過filtered
12. 12
    濃縮concentrated to dryness in vacuo

実験手順

To a stirred suspension of 5.3 g (10.0 mmol) of [S-(R*,R*)]-2-[2-[2-(1-carboxy-2-methylbutylcarbamoyl) phenyldisulfanylbenzoylamino]-3-methylpentanoic acid (from Preparation 19) in 200 mL of dichloromethane was added dropwise 2.4 g (15.0 mmol) of liquid bromine. The reaction mixture was stirred at room temperature for 2 hours and concentrated to dryness in vacuo. The residue was triturated with dichloromethane. The dichloromethane was removed by evaporation in vacuo to remove excess bromine. The residue was partitioned between dichloromethane/5% aqueous sodium bicarbonate (200 mL each). The aqueous layer was separated, washed with fresh dichloromethane, and acidified to pH 1.5 with 6.0M hydrochloric acid. The acidic aqueous solution was extracted with dichloromethane (2×75 mL). The organic layers were combined, washed with water, dried (MgSO4), filtered and concentrated to dryness in vacuo to give 4.8 g of the title compound, mp 50°-52° C.

出典