Isopropanol → HCID 136453564, compound

Participants

Reaction Steps

To a suspension of 29.2g of 7β-amino-3-acetoxymethyl-3-cephem-4-carboxylic acid in 600 ml of methanol was added 18.1g of dicyclohexylamine and stirred at room temperature for 1 hour. To a semitransparent solution thus obtained was added 24.0g of 4-hydroxy-3,5-di-tert.-butylbenzaldehyde and stirred at room temperature for 2 hours and stirring was continued after adding 50g of molecular sieve 3A for further 5 hours. After filtration of the reaction mixture, the filtrate was condensed under reduced pressure to give a crystalline product which after an addition of isopropanol was collected by filtration. To a solution of 13.4g of dicyclohexylammonium 7β-(4-hydroxy-3,5-di-tert.-butylbenzylideneamino)-3-acetoxymethyl-3-cephem-4-carboxylate thus obtained in 200 ml of methanol was added dropwise 4.74g of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone in 40 ml of methanol at -15° C, and after completion of the addition the stirring was continued for another 10 minutes at the same temperature and then 1g of 2,6-di-tert.-butyl-p-cresol was added to the reaction mixture. After stirring for another 10 minutes at 0° C, 5.60 ml of triethylamine was added to the solution, which was then condensed to about 50 ml under reduced pressure, diluted with 300 to 400 ml of chloroform and washed three times with the same volume of water. On drying over anhydrous magnesium sulfate the solvent was removed under reduced pressure, the residue extracted with ether, the extract was condensed and added with n-hexane to give a precipitate, which was collected by filtration affording 13.03g of the desired product as a yellow powder. Crystallization of this powder from n-hexane-chloroform yielded a pure sample melting at 139°-141° C.

Provenance & Evidence