4-Methylmorpholine → Cefaclor

Temperatur

-40 °C

To a mixture of 162 g of ethyl 3-α-carboxybenzylaminocrotonate potassium salt, 450 ml of dimethylformamide and 900 ml of acetonitrile, cooled to -40° C., 1.5 ml of 4-methylmorpholine and 54 ml of ethyl chloroformate are added. The mixture is stirred one hour at -40° C., then a previously cooled solution of triethylamine salt of 7-amino-3-chloro-3-cephem-4-carboxylic acid (corresponding to 99 g of free acid) in 900 ml of a mixture acetonitrile/water 1/1 (v/v) is added thereinto. The solution is kept in the cool for about 3 hours, then it is treated with 630 ml of water and filtered. The filtrate is made acid to pH 1.5 with 6N hydrochloric acid, then the pH is adjusted to 4.5 with triethyl amine. The suspension thus obtained is kept to 0° C. overnight, then it is filtered. The product thus obtained is washed with acetonitrile/water 1/1 (v/v) and dried under vacuum at 35° C. Thus, 120 g of amorphous raw cefaclor are obtained.

1. temperaturecool for about 3 hours
2. filtrationfiltered
3. customThe suspension thus obtained
4. waitis kept to 0° C. overnight
5. filtrationit is filtered
6. customThe product thus obtained
7. washis washed with acetonitrile/water 1/1 (v/v)
8. customdried under vacuum at 35° C

ORD-Eintrag

ord-6ff14aa7c86445708fc5015c99517a4d

Quelldatensatz

uspto-grants-1996_12

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05589593