Abstract: The present application relates to methods of preparing 5R-[(benzyloxy) amino] piperidine-2S-carboxylic acid or its derivatives in an environment-friendly way. The method uses L-glutamic acid as a starting material, which is first subjected to esterification reaction in the presence of an acidic reagent, and then reacted successively with 2-haloacetate and N-protecting agent, or with N-protecting agent and 2-haloacetate under a basic condition to obtain compound IV; then, the obtained compound IV is subjected to intramolecular condensation into a ring under the action of a strong base to obtain N-protecting group piperidine-5-one-2S-carboxylate (V).

Abstract: The present application relates to methods of preparing 5R-[(benzyloxy) amino] piperidine-2S-carboxylic acid or its derivatives in an environment-friendly way. The method uses L-glutamic acid as a starting material, which is first subjected to esterification reaction in the presence of an acidic reagent, and then reacted successively with 2-haloacetate and N-protecting agent, or with N-protecting agent and 2-haloacetate under a basic condition to obtain compound IV; then, the obtained compound IV is subjected to intramolecular condensation into a ring under the action of a strong base to obtain N-protecting group piperidine-5-one-2S-carboxylate (V).

Abstract: A method for preparing an intermediate for avibactam, and specifically relates to a method for preparing ({[(2S,5R)-2-carbamoyl-7-oxo-1,6-diazabicyclo[3.2.1]oct-6-yl]oxy}sulfonyl)tetrabutylammonium salt (II). With 5R-[(benzyloxy) amino] piperidine-2S-carboxylate oxalate (III) as the raw material is reacted with the amide of Formula IV via amidation to prepare the compound of Formula V; the resulting compound of Formula V is reacted with the carbonylation reagent via urea cyclization to obtain the compound of Formula VI; the benzyl or the substituted benzyl in the compound of Formula VI is removed by catalytic hydrogeneration, then the resulting compound is sulfatated by sulfur trioxide complex and is salinized into tetrabutylammonium to obtain the final product (II).

Abstract: A method for preparing an intermediate for avibactam, and specifically relates to a method for preparing ({[(2S,5R)-2-carbamoyl-7-oxo-1,6-diazabicyclo[3.2.1]oct-6-yl]oxy}sulfonyl)tetrabutylammonium salt (II). With 5R-[(benzyloxy) amino] piperidine-2S-carboxylate oxalate (III) as the raw material is reacted with the amide of Formula IV via amidation to prepare the compound of Formula V; the resulting compound of Formula V is reacted with the carbonylation reagent via urea cyclization to obtain the compound of Formula VI; the benzyl or the substituted benzyl in the compound of Formula VI is removed by catalytic hydrogeneration, then the resulting compound is sulfatated by sulfur trioxide complex and is salinized into tetrabutylammonium to obtain the final product (II).