Korea Institute of Science and Technology

Hyen Joo Son

Sung Hoon Kim

Ghil Soo Nam

Joong Heon Kim

Ha Young Kim

Ha Yeon Kim

Joong-Hyup Kim

Eun S Jang

1-N-ethylsisomicin represented by the following structural formula I and pharmaceutically acceptable salts thereof are useful antibacterial agents and can be prepared in high yields by a characteristic method comprising the steps of: chelating sisomicin with a chelating agent in a protic solvent; protecting the 3-,2'-and 6'-amino groups of the chelated sisomicin derivative with an acylating reagent; removing the chelating metal from the sisomicin derivative by use of ammonia water, to obtain a 3, 2', 6-N-trisubstituted sisomicin derivative; reacting the trisubstituted sisomicin derivative with an ethylating reagent in an aprotic organic solvent, to selectively ethylate the 1-amino group of the trisubstituted sisomicin derivative; and deprotecting the ethylated sisomicin derivative: ##STR1##

Method for preparing 1-N-ethylsisomicin

Novel cephalosporin compounds of formula (I) exhibit potent and broad antibiotic activities against Gram-negative and Gram-positive bacteria and various resistant bacteria: ##STR1##

Cephalosporin compounds

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Seoul, South Korea

Hyen Joo Son