Trifluoroacetic acid → Triphenylcarbinol

Participants

Reaction Steps

2 g of the product of Step B were added with stirring at room temperature to 20 ml of trifluoroacetic acid held under nitrogen and after stirring for 10 minutes at room temperature, the mixture was concentrated under vacuum to a volume of 8 ml. The mixture was cooled in an ice water bath and 60 ml of isopropyl ether were slowly added thereto. The mixture was stirred for 10 minutes at room temperature and was vacuum filtered and the filter was rinsed with isopropyl ether. The filtrate was evaporated to dryness under reduced pressure to obtain 1.5 g of raw product. The latter was placed under an argon atmosphere and 7.5 ml of 50% aqueous formic acid were added thereto. The mixture was stirred at 40° C. for 15 minutes and was then vacuum filtered. The recovered product was rinsed twice with 1 ml of 50% aqueous formic acid and 3 times with 1 ml of distilled water to obtain 319 mg of triphenyl carbinol. The filtrate was distilled to dryness and ethanol was added. The mixture was triturated with 15 ml of ether and was vacuum filtered. The recovered product was rinsed with ether and dried to obtain 0.973 g of the syn isomer of 3-methyl-7-[2-(2-amino-4-thiazolyl)-2-hydroxyimino-acetamido]-ceph-3 -eme-4-carboxylic acid with an Rf=0.3 (acetone containing 10% water).

Provenance & Evidence