Phosphoric Acid → (6R,7R)-3-Hydroxymethyl-7-[2-(fur-2-yl)-2-methoxyiminoacetamido]ceph-3-em-4-carboxylic acid

Participants

Reaction Steps

A reaction mixture consisting of (6R,7R)-7-[2-(fur-2-yl)-2-methoxyiminoacetamido]-3-acetoxymethylceph-3-em-4-carboxylic acid (syn isomer) (8.0 g), sodium hydroxide (2.6 g), demineralised water (120 ml), orthophosphoric acid (2.2 ml) and a slurry (18 ml) of Rhodosporidium toruloides CBS14 prepared as in (a) above was incubated at 25°C on an orbital shaker. After 20 hr. it was shown by t.l.c. (silica gel plates with 0.5M sodium chloride as solvent) that the reaction was complete. The reaction mixture was centrifuged, and the supernatant decanted and filtered through an asbestos pad. Methyl isobutyl ketone (14 ml) was added to the clear filtrate, the mixture was magnetically stirred and a 20% solution of orthophosphoric acid was added dropwise until the pH was 2.0. The mixture was then allowed to settle, the lower aqueous layer pipetted off and the solvent layer containing a copious white precipitate was vacuum filtered. The precipitate was washed with methyl isobutyl ketone (10 ml) and ice cold water (2 × 10 ml). The product was then sucked dry and dried in vacuo at room temperature to yield title compound (5.01 g). IR and NMR spectra of the product were consistent with it being title compound. The purity was estimated to be 92.2% by HPLC.

Provenance & Evidence