反応 #444658

反応方程式

ampicillin

HCl

→

title compound

Ampicillin Trihydrate

反応条件

後処理

1. 1
   温度while cooling with ice
2. 2
   その他The aqueous phase is separated off
3. 3
   抽出the organic phase back-extracted with a mixture of 5.4 ml concentrated HCl and 44.5 ml water
4. 4
   ろ過The combined aqueous phases are filtered through a filtering aid
5. 5
   workup.ADDITIONpumped into a suspension of 5 g ampicillin trihydrate seed crystals in 100 ml water keeping the pH from 4.5 to 5.0
6. 6
   workup.ADDITIONby the addition of concentrated aqueous ammonia

実験手順

The resultant crude protected ampicillin mixture is worked up by treating with a mixture of 289 ml ice-water and 39.6 ml concentrated HCl and stirred for 30 minutes while cooling with ice. The aqueous phase is separated off and the organic phase back-extracted with a mixture of 5.4 ml concentrated HCl and 44.5 ml water. The combined aqueous phases are filtered through a filtering aid and pumped into a suspension of 5 g ampicillin trihydrate seed crystals in 100 ml water keeping the pH from 4.5 to 5.0 by the addition of concentrated aqueous ammonia. The title compound is obtained by standing the mixture overnight in a refrigerator, isolating the crystals, and washing them with 60 ml ice-water and 3×50 ml 90% acetone, followed by drying. Yield 61.6 g=82.4%, Purity 98.8%.

出典