Abstract: This invention provides a penicillin derivative of the formula ##STR1## wherein R.sub.1 and R.sub.2 are the same or different and represent hydrogen, C.sub.1-6 alkyl, C.sub.1-6 hydroxyalkyl, C.sub.3-9 acyloxyalkyl, C.sub.8-13 benzyloxyalkyl, C.sub.2-7 alkoxyalkyl, C.sub.2-7 alkoxycarbonyl, C.sub.3-8 alkenyloxycarbonyl, C.sub.3-8 alkynyloxycarbonyl, phenyl, amino, cyano, formyl, trifluoromethyl, C.sub.2-6 acyl, carbamoyl, C.sub.2-7 alkylcarbamoyl, benzyloxycarbonylamino, C.sub.2-7 alkoxycarbonylamino; and R.sub.3 is hydrogen, a group for forming a pharmaceutically acceptable salt, or a penicillin carboxyl protecting group, with the proviso that both of R.sub.1 and R.sub.2 are not hydrogen or C.sub.2-7 alkoxycarbonyl at the same time and that when one of R.sub.1 and R.sub.2 is hydrogen, the other is not C.sub.2-7 alkoxycarbonyl, or a pharmaceutically acceptable acid addition salt, process for preparing the derivative, and a pharmaceutical composition containing the derivative.

Abstract: A penicillin derivative represented by the following formula ##STR1## wherein R.sub.1 is hydrogen or trialkylsilyl; R.sub.2 is hydrogen, trialkylsilyl or COOR.sub.2 ' wherein R.sub.2 ' is hydrogen, C.sub.1-18 alkyl, C.sub.2-7 alkoxymethyl, C.sub.3-8 alkylcarbonyloxymethyl, C.sub.4-9 alkylcarbonyloxyethyl, (C.sub.5-7 cycloalkyl)carbonyloxymethyl, C.sub.9-14 benzylcarbonyloxyalkyl, C.sub.3-8 alkoxycarbonylmethyl, C.sub.4-9 alkoxycarbonylethyl, phthalidyl, crotonolacton-4-yl, .gamma.-butyrolacton-4-yl, halogenated C.sub.1-6 alkyl substituted with 1 to 3 halogen atoms, C.sub.1-6 alkoxy- or nitro-substituted or unsubstituted benzyl, benzhydryl, tetrahydropyranyl, dimethylaminoethyl, dimethylchlorosilyl, trichlorosilyl, (5-substituted C.sub.1-6 alkyl or phenyl or unsubstituted-2-oxo-1,3-dioxoden-4-yl)methyl, C.sub.8-13 benzoyloxyalkyl or group for forming a pharmaceutically acceptable salt; and R.sub.3 has the same meaning as above R.sub.2 '.

Abstract: A penicillin derivative represented by the following formula ##STR1## wherein R.sub.1 and R.sub.2 are each the same or different and represent hydrogen, C.sub.1-18 alkyl, mononitro-substituted benzyl or group for forming a pharmaceutically acceptable salt and R.sub.3 is selected from the group consisting of hydrogen, C.sub.1-6 alkyl, C.sub.2-7 alkoxymethyl, C.sub.3-8 alkylcarbonyloxymethyl, C.sub.4-9 alkylcarbonyloxyethyl, (C.sub.5-7 cycloalkyl)carbonyloxymethyl, C.sub.9-14 benzylcarbonyloxyalkyl, C.sub.3-8 alkoxycarbonylmethyl, C.sub.4-9 alkoxycarbonylethyl, phthalidyl, crotonolacton-4-yl, .gamma.-butyrolacton-4-yl, halogenated C.sub.1-6 alkyl substituted with 1 to 3 halogen atoms, C.sub.1-6 alkoxy- or nitro-substituted or unsubstituted benzyl, benzhydryl, tetrahydropyranyl, dimethylaminoethyl, dimethylchlorosilyl, trichlorosilyl, (5-substituted C.sub.1-6 alkyl or phenyl or unsubstituted-2-oxo-1,3-dioxoden-4-yl)methyl, C.sub.8-13 benzoyloxyalkyl and group for forming a pharmaceutically acceptable salt.

Abstract: A penicillin derivative represented by the following formula, a pharmaceutically acceptable salt thereof and an ester thereof: ##STR1## wherein n is 0, 1 or 2 and process for preparing the same.

Abstract: This invention provides a penicillin derivative of the formula and a salt thereof ##STR1## wherein X represents chlorine atom or bromine atom and R represents hydrogen atom or penicillin carboxy-protecting radical, and a process for preparing the derivative of the formula (I) and a salt thereof by reacting a compound of the formula ##STR2## wherein R is as defined above with a chlorinating reagent or brominating reagent and, when required, forming a salt thereof.