تفاعل #3361

معادلة التفاعل

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

المذيبات

dichloromethane

ظروف التفاعل

المعالجة

1. 1
   تركيزconcentrated to dryness in vacuo
2. 2
   أخرىThe residue was triturated with dichloromethane
3. 3
   أخرىThe dichloromethane was removed by evaporation in vacuo
4. 4
   أخرىto remove excess bromine
5. 5
   أخرىThe residue was partitioned between dichloromethane/5% aqueous sodium bicarbonate (200 mL each)
6. 6
   أخرىThe aqueous layer was separated
7. 7
   غسيلwashed with fresh dichloromethane
8. 8
   استخلاصThe acidic aqueous solution was extracted with dichloromethane (2×75 mL)
9. 9
   غسيلwashed with water
10. 10
    تجفيفdried (MgSO4)
11. 11
    ترشيحfiltered
12. 12
    تركيزconcentrated to dryness in vacuo

الإجراء التجريبي

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.

المصدر