Hydrochloric Acid → Ampicillin Trihydrate

Participants

Reaction Steps

The mixture obtained in step a) is added dropwise to the mixture obtained in step b) at a temperature of -45/-35°. The resultant mixture is stirred for 2 hours at a temperature of -15/-35°. The resultant crude protected ampicillin mixture is worked up by treating with a mixture of ice-water and concentrated hydrochloric acid and stirred for 20 minutes while cooling with ice. The aqueous phase is separated off and the organic phase is reextracted with a mixture of water and concentrated hydrochloric acid. The combined aqueous phases are treated with concentrated aqueous sodium hydroxide to a pH of 4.5/5.5. Ampicillin trihydrate crystallizes out of the reaction mixture overnight in a refrigerator, the crystals are isolated, washed with IPA 88% and dried. Yield 89.0%, Purity 98.4%.

Provenance & Evidence