The present disclosure provides a method for preparing a 7-alkoxyoxacephem intermediate compound, the method comprising a process (S1) including: reacting a compound represented by a following chemical formula 1 with a halogen compound in an organic solvent to form a reaction product such that unreacted halogen compound remains; and adding metal alkoxide and reducing agent to the reaction product with the unreacted halogen compound remaining, thereby to produce a compound represented by a following chemical formula 2: ##STR00001##
where R is a Cl, Br, I, halogen derivative, R.sub.1 is a carboxyl protecting group including diphenylmethyl, p-methoxybenzyl, p-nitrobenzyl or hydrogen (H), and R.sub.2 is an alkyl group having 1 to 4 carbon atoms.

The present disclosure provides a method for preparing a 7-alkoxyoxacephem intermediate compound, the method comprising a process (S1) including: reacting a compound represented by a following chemical formula 1 with a halogen compound in an organic solvent to form a reaction product such that unreacted halogen compound remains; and adding metal alkoxide and reducing agent to the reaction product with the unreacted halogen compound remaining, thereby to produce a compound represented by a following chemical formula 2: ##STR00001##
where R is a Cl, Br, I, halogen derivative, R.sub.1 is a carboxyl protecting group including diphenylmethyl, p-methoxybenzyl, p-nitrobenzyl or hydrogen (H), and R.sub.2 is an alkyl group having 1 to 4 carbon atoms.

A refining method of a midbody of latamoxef sodium includes: dissolving 7-amino-7-methoxy-3-(5-tetrazolyl)thiomethyl-1-oxa-3-cephem-4-carboxylic acid in dichloromethane, and then dividing into a dichloromethane layer and a water layer; extracting the dichloromethane layer, adding a NaHCO.sub.3 solution to stir, and remaining an organic layer after stratification; stirring, crystallizing and filtering the organic layer in turn, to obtain a filtrate, preparing a second powder by stirring the filtrate under conditions of a catalyst and a normal temperature; preparing a first powder by extracting the water layer, dropping the hydrochloric acid to adjust a pH value thereof, performing crystal cultivation and suction filtration after performing cooling, and then performing vacuum drying; combining the first powder and the second powder to prepare the midbody of latamoxef sodium: 73-amino-7-methoxy-3-(5-tetrazolyl)thiomethyl-1-oxa-3-cephem-4-carboxylic acid, which has a yield of 95.6-96.8% and a purity of 99.2-99.5%.

A refining method of a midbody of latamoxef sodium includes: dissolving 7-amino-7-methoxy-3-(5-tetrazolyl)thiomethyl-1-oxa-3-cephem-4-carboxylic acid in dichloromethane, and then dividing into a dichloromethane layer and a water layer; extracting the dichloromethane layer, adding a NaHCO.sub.3 solution to stir, and remaining an organic layer after stratification; stirring, crystallizing and filtering the organic layer in turn, to obtain a filtrate, preparing a second powder by stirring the filtrate under conditions of a catalyst and a normal temperature; preparing a first powder by extracting the water layer, dropping the hydrochloric acid to adjust a pH value thereof, performing crystal cultivation and suction filtration after performing cooling, and then performing vacuum drying; combining the first powder and the second powder to prepare the midbody of latamoxef sodium: 73-amino-7-methoxy-3-(5-tetrazolyl)thiomethyl-1-oxa-3-cephem-4-carboxylic acid, which has a yield of 95.6-96.8% and a purity of 99.2-99.5%.

The present disclosure provides a method for preparing a 7-alkoxyoxacephem intermediate compound, the method comprising a process (S1) including: reacting a compound represented by a following chemical formula 1 with a halogen compound in an organic solvent to form a reaction product such that unreacted halogen compound remains; and adding metal alkoxide and reducing agent to the reaction product with the unreacted halogen compound remaining, thereby to produce a compound represented by a following chemical formula 2:

##STR00001## where R is a Cl, Br, I, halogen derivative, R.sub.1 is a carboxyl protecting group including diphenylmethyl, p-methoxybenzyl, p-nitrobenzyl or hydrogen (H), and R.sub.2 is an alkyl group having 1 to 4 carbon atoms.

The present disclosure provides a method for preparing a 7-alkoxyoxacephem intermediate compound, the method comprising a process (S1) including: reacting a compound represented by a following chemical formula 1 with a halogen compound in an organic solvent to form a reaction product such that unreacted halogen compound remains; and adding metal alkoxide and reducing agent to the reaction product with the unreacted halogen compound remaining, thereby to produce a compound represented by a following chemical formula 2:

##STR00001## where R is a Cl, Br, I, halogen derivative, R.sub.1 is a carboxyl protecting group including diphenylmethyl, p-methoxybenzyl, p-nitrobenzyl or hydrogen (H), and R.sub.2 is an alkyl group having 1 to 4 carbon atoms.

A refining method of a midbody of latamoxef sodium includes: dissolving 7-amino-7-methoxy-3-(5-tetrazolyl)thiomethyl-1-oxa-3-cephem-4-carboxylic acid in dichloromethane, and then dividing into a dichloromethane layer and a water layer; extracting the dichloromethane layer, adding a NaHCO.sub.3 solution to stir, and remaining an organic layer after stratification; stirring, crystallizing and filtering the organic layer in turn, to obtain a filtrate, preparing a second powder by stirring the filtrate under conditions of a catalyst and a normal temperature; preparing a first powder by extracting the water layer, dropping the hydrochloric acid to adjust a pH value thereof, performing crystal cultivation and suction filtration after performing cooling, and then performing vacuum drying; combining the first powder and the second powder to prepare the midbody of latamoxef sodium: 73-amino-7-methoxy-3-(5-tetrazolyl)thiomethyl-1-oxa-3-cephem-4-carboxylic acid, which has a yield of 95.6-96.8% and a purity of 99.2-99.5%.

A refining method of a midbody of latamoxef sodium includes: dissolving 7-amino-7-methoxy-3-(5-tetrazolyl)thiomethyl-1-oxa-3-cephem-4-carboxylic acid in dichloromethane, and then dividing into a dichloromethane layer and a water layer; extracting the dichloromethane layer, adding a NaHCO.sub.3 solution to stir, and remaining an organic layer after stratification; stirring, crystallizing and filtering the organic layer in turn, to obtain a filtrate, preparing a second powder by stirring the filtrate under conditions of a catalyst and a normal temperature; preparing a first powder by extracting the water layer, dropping the hydrochloric acid to adjust a pH value thereof, performing crystal cultivation and suction filtration after performing cooling, and then performing vacuum drying; combining the first powder and the second powder to prepare the midbody of latamoxef sodium: 73-amino-7-methoxy-3-(5-tetrazolyl)thiomethyl-1-oxa-3-cephem-4-carboxylic acid, which has a yield of 95.6-96.8% and a purity of 99.2-99.5%.