Abstract: A process for preparing a diazabicyclooctane compound represented by the following formula (I): wherein A represents RcO—; B represents NH or NC1-6 alkyl; C represents a benzyl group; Rc represents a C1-6 alkyl group; A is substituted with one substituent Fn1, wherein Fn1 represents an azetidine group; the process including: (a) silylating the compound represented by the following formula (IV-c): wherein in the formula (IV-c), OBn represents benzyloxy, and (b) carrying out an intramolecular urea formation reaction.

Abstract: A diazabicyclooctane compound, which is a beta-lactame inhibitor, represented by the following formula (I): wherein A represents Ra(Rb)N— or RcO—; B represents NH or NC1-6 alkyl; C represents benzyl, H or SO3M, wherein M represents H, an inorganic or an organic cation; Ra and Rb represent H, C1-6 alkyl or acyl; Rc represents C1-6 alkyl or a heterocyclyl; A is unsubstituted or substituted with 0 to 4 substituents Fn1, wherein Fn1 represents C1-6 alkyl, O?, or Rg-(CH2)0-3—, wherein Rg represents a heterocyclyl, phenyl, heteroaryl, acyl, RdO2S—, Re(Rf)N—, Re(Rf)NCO—, ReO—, ReOCO— or a protective group, wherein Rd represents C1-6 alkyl or MO—; Re and Rf represent H or C1-6 alkyl, and a heterocycle having at least one nitrogen atom may be formed between Ra and Rb, between Rc and B, or between Re and Rf.

Abstract: A crystalline form of a diazabicyclooctane derivative represented by the following Formula (VII), and processes for producing the same:

Abstract: A process for producing a diazabicyclooctane derivative represented by Formula (IV) and intermediates thereof by carrying out the following steps: wherein P is an NH protecting group capable of being removed with acid; R1 is 2,5-dioxopyrrolidin-1-yl, 1,3-dioxo-3a,4,7,7a-tetrahydro-1H-isoindol-2(3H)-yl, 1,3-dioxohexahydro-1H-isoindol-2(3H)-yl, or 3,5-dioxo-4-azatricyclo[5.2.1.02.6]dec-8-en-4-yl; R2 is hydrogen, ClCO— or Cl3COCO—; R3 is C1-6 alkyl or heterocyclyl, or forms a 3- to 7-membered heterocyclic ring together with the —O—NH— to which it is attached; and OBn is benzyloxy.

Abstract: A diazabicyclooctane compound, which is a beta-lactame inhibitor, represented by the following formula (I): wherein A represents Ra(Rb)N— or RcO—; B represents NH or NC1-6 alkyl; C represents benzyl, H or SO3M, wherein M represents H, an inorganic or an organic cation; Ra and Rb represent H, C1-6 alkyl or acyl; Rc represents C1-6 alkyl or a heterocyclyl; A is unsubstituted or substituted with 0 to 4 substituents Fn1, wherein Fn1 represents C1-6 alkyl, O?, or Rg-(CH2)0-3—, wherein Rg represents a heterocyclyl, phenyl, heteroaryl, acyl, RdO2S—, Re(Rf)N—, Re(Rf)NCO—, ReO—, ReOCO— or a protective group, wherein Rd represents C1-6 alkyl or MO—; Re and Rf represent H or C1-6 alkyl, and a heterocycle having at least one nitrogen atom may be formed between Ra and Rb, between Rc and B, or between Re and Rf.

Abstract: A diazabicyclooctane compound, which is a beta-lactame inhibitor, represented by the following formula (I): wherein A represents Ra(Rb)N— or RcO—; B represents NH or NC1-6 alkyl; C represents benzyl, H or SO3M, wherein M represents H, an inorganic or an organic cation; Ra and Rb represent H, C1-6 alkyl or acyl; Rc represents C1-6 alkyl or a heterocyclyl; A is unsubstituted or substituted with 0 to 4 substituents Fn1, wherein Fn1 represents C1-6 alkyl, O?, or Rg-(CH2)0-3—, wherein Rg represents a heterocyclyl, phenyl, heteroaryl, acyl, RdO2S—, Re(Rf)N—, Re(Rf)NCO—, ReO—, ReOCO— or a protective group, wherein Rd represents C1-6 alkyl or MO—; Re and Rf represent H or C1-6 alkyl, and a heterocycle having at least one nitrogen atom may be formed between Ra and Rb, between Rc and B, or between Re and Rf.

Abstract: A diazabicyclooctane compound, which is a beta-lactame inhibitor, represented by the following formula (I): wherein A represents Ra(Rb)N— or RcO—; B represents NH or NC1-6 alkyl; C represents benzyl, H or SO3M, wherein M represents H, an inorganic or an organic cation; Ra and Rb represent H, C1-6 alkyl or acyl; Rc represents C1-6 alkyl or a heterocyclyl; A is unsubstituted or substituted with 0 to 4 substituents Fn1, wherein Fn1 represents C1-6 alkyl, O?, or Rg-(CH2)0-3—, wherein Rg represents a heterocyclyl, phenyl, heteroaryl, acyl, RdO2S—, Re(Rf)N—, Re(Rf)NCO—, ReO—, ReOCO— or a protective group, wherein Rd represents C1-6 alkyl or MO—; Re and Rf represent H or C1-6 alkyl, and a heterocycle having at least one nitrogen atom may be formed between Ra and Rb, between Rc and B, or between Re and Rf.

Abstract: A compound represented by the following general formula (I) or a salt thereof: wherein R&agr; represents a C1-C10 alkyl group, a C3-C10 alkenyl group, a C7-C15 aralkyl group, a quinolinylalkyl group, a quinolinylalkenyl group, a C2-C10 alkylcarbonyl group, a C7-C15 aralkylcarbonyl group, a C4-C7 cycloalkylcarbonyl group, benzoyl group, an imidazolylcarbonyl group and the like; R1 represents hydrogen atom, a C1-C10 alkyl group, or a C2-C10 alkylcarbonyl group; and R2 represents hydrogen atom, a C1-C10 alkyl group, or a C2-C10 alkylcarbonyl group, provided that the compound wherein R&agr; represents a C2-C10 alkylcarbonyl group and both of R1 and R2 represent a C1-C10 alkyl group is excluded.