CEPHALEXIN MONOHYDRATE

Description

Cephalexin was first synthesized in 1967 by Glaxo Research Laboratories and first produced on an industrial scale by Eli Lilly & Co. in the same year. It is a deacetoxylated derivative of cephaloglycin that is not metabolized in vivo. When administered orally, it shows a much higher serum concentration and much lower tendency to induce diarrhea than cephaloglycin. Cephalexin has been used widely and is the most popular orally active antibiotic in the world for treatment of respiratory tract, urinary tract, surgical, ear and nose, and other infections caused by Staphylococcus, Streptococcus, Escherichia coli, Klebsiella, Enterobacter, and Proteus.

Chemical properties

White to Off-White Solid

Originator

Ceporex,Glaxo,UK,1970

The Uses of CEPHALEXIN MONOHYDRATE

Cephalosporin antibacterial.

The Uses of CEPHALEXIN MONOHYDRATE

A semisynthetic cephalorsporin antibiotic.

The Uses of CEPHALEXIN MONOHYDRATE

Semi-synthetic cephalosporin antibiotic.

Definition

ChEBI: The hydrate of cephalexin.

Manufacturing Process

To a 1 liter flask containing dimethylformamide at 0°C, was added 24.8 g sodium N-(2-methoxycarbonyl-1-methylvinyl)-D-α-phenylglycine (prepared from sodium D-α-phenylglycine and methyl acetoacetate). The mixture was cooled to -40°C and methyl chloroformate (7.5 ml) and dimethylbenzylamine (0.26 ml) added. After stirring for 25 minutes, p-nitrobenzyl 7- aminodesacetoxycephalosporanate (32.8 g) in the form of its hydrochloride salt was added, followed by triethylamine (12.1 ml) and dimethylformamide (140 ml) over a period of 20 minutes. The reaction mixture was stirred for 2 hours at -25°C to -35°C, then warmed to 0°C and water (32 ml) added. To the resultant solution, hydrochloric acid (54 ml) was added followed by zinc (21.8 g) in portions over a period of 5 minutes, the temperature being maintained at 5°C to 10°C. Further hydrochloric acid (35 ml) was added and the solution stirred at 15°C to 20°C for 7 hours.
The pH was adjusted to 3.3 with triethylamine and semicarbazidehydrochloride (9.5 g) added. The mixture was brought back to pH 3 with further triethylamine, then stirred for 30 minutes at pH 3. The resultant mixture was adjusted slowly over 4 hours to pH 6.8 by addition of triethylamine, seeding being carried out when pH 4.5 was reached. The precipitated cephalexin was filtered off, washed with dimethylformamide (200 ml) and the cephalexin recovered, yield 75%.

brand name

Keflex (Panixine (Ranbaxy).

Therapeutic Function

Antibiotic