Abstract: A process for preparing hydrochloride of 3-acetoxy-2,3-dihydro-5-[2-(dimethylamino)ethyl]-2-(p-methoxyphenyl)-1,5-b enzothiazepin-4(5H)-one which comprises reacting 3-hydroxy-2,3-dihydro-5-[2-(dimethylamino)ethyl]-2-(p-methoxyphenyl)-1,5-b enzothiazepin-4(5H)-one which acetyl chloride in acetic acid or a mixed solvent of acetic acid and acetic anhydride. According to the process, hydrochloride of 3-acetoxy-2,3-dihydro-5-[2-(dimethylamino)ethyl]-2-(p-methoxyphenyl)-1,5-b enzothiazepin-4(5H)-one is readily obtained in one step.

Abstract: A stable trihydrate of (2S, 5R, 6R)-6-{(2R)-2-[(2R)-2-amino-3-(N-methylcarbamoyl)propionamido]-2-(p-hydrox yphenyl)acetamido}-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-c arboxylic acid and process for preparing the same are disclosed.

Abstract: A cephalosporin compound of the formula: ##STR1## wherein: R.sup.2 is a group of the formula: ##STR2## R.sup.4 is a lower alkenyl group, a lower alkyl group or a lower alkyl group substituted with a member selected from the group consisting of cyano, lower alkylthio, 2-(lower alkyl)-1,3,4-thiadiazol-5-yl, carbamoyl, thiocarbamoyl, and N-lower alkyl(thiocarbamoyl) andR.sup.5 and R.sup.6 are each a hydrogen atom or a lower alkyl group, or a pharmaceutically acceptable salt thereof, is disclosed. These compounds have antimicrobial activity.

Abstract: A cephalosporin compound of the formula: ##STR1## wherein R.sup.1 is a protected or unprotected amino group;either one of R.sup.2 and R.sup.3 is a substituted or unsubstituted lower alkylthio group; sulfamoyl group; a lower alkylsulfonyl group; sulfo group; a substituted or unsubstituted amino group; a lower alkyl group; a lower alkyl group having a substituent selected from a lower alkylthio group, amino group and an acylamino group; a halogen atom; carboxy group or a lower alkoxy group; andthe other one of R.sup.2 and R.sup.3 is hydrogen atom; carbamoyl group; a substituted or unsubstituted amino group; a lower alkyl group or a hydroxy-lower alkyl group; orR.sup.2 and R.sup.3 are combined together to form a lower alkylene group;or a salt thereof and processes for preparing the same are disclosed. The cephalosporin compound (I) is useful as an antimicrobial agent.

Abstract: A cephalosporin compound of the formula: ##STR1## wherein R.sup.1 is a hydrogen atom, a lower alkyl group, a carboxy(lower)alkyl group, a hydroxy(lower)alkyl group, a carbamoyl(lower)alkyl group, an N-(lower)alkyl-carbamoyl(lower)alkyl group, a cycloalkyl group, a carboxycycloalkyl group, or a tetrazolylmethyl group, R.sup.2 is a hydrogen atom, a lower alkyl group, a formyl group or a lower alkanol group, R.sup.3 is a hydrogen atom, or R.sup.2 and R.sup.3 are combined together to form an aralkylidene group, or a pharmaceutically acceptable salt thereof which is useful as an antimicrobial agent, and process for their preparation.

Abstract: A 7.beta.-{(Z)-2-(2-aminothiazol-4-yl)-2-[(2-pyrrolidon-3-yl)oxyimino]acetam ido}-3-(1-amino-1H-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid or a pharmaceutically acceptable salt thereof is useful as an antimicrobial agent.

Abstract: A compound of the formula: ##STR1## wherein R.sup.1 is hydrogen or hydroxy, R.sup.2 is a group of the formula: --CO-CH(NH.sub.2)-CH.sub.2 COR.sup.3 or --COCH.sub.2 -CH(NH.sub.2)-COR.sup.3, and R.sup.3 is selected from the group consisting of hydroxy, lower alkylamino, di-lower alkylamino, lower alkoxy and hydroxy-lower alkylamino, or R.sup.3 is amino when R.sup.2 is hydroxy. Several methods of preparing the compound [I] are also disclosed. The compound [I] and a pharmaceutically acceptable salt thereof are useful as antimicrobial agents.