Oxalyl chloride → (6R)-8-Oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid

2.66 g of 2-(2-tritylaminothiazol-4-yl)-(Z)-2-methoxyiminoacetic acid and 3 ml of dimethylacetamide were dissolved in 50 ml of dichloromethane, and a solution of 0.78 ml of oxalyl chloride in 2 ml of dichloromethane was added gradually thereto at -17° to -15° C. under stirring. After the mixture was stirred at the same temperature for 10 minutes, a solution of 3.22 g of 7β-amino-3-[(1-formamido-1H-tetrazol-5-yl)thiomethyl]-3-cephem-4-carboxylic acid and 3.66 g of triethylamine in dichloromethane (40 ml)-dimethylacetamide (30 ml) was added dropwise thereto at -17° to -13° C. for 15 minutes. Then, the mixture was stirred at -18° for 3 hours. After the reaction, the mixture was evaporated under reduced pressure to remove solvent. Water was added to the residue, and the aqueous solution was washed with ethyl acetate, adjusted to pH 3 with citric acid and then extracted twice with a mixture of 20 ml of ethyl acetate and 5 ml of tetrahydrofuran. The extracts were combined, washed with water, dried and evaporated under reduced pressure to remove solvent. Ether was added to the residue thus obtained, whereby 2.87 g of 7β-[2-(2-tritylaminothiazol-4-yl)-(Z)-2-methoxyiminoacetamido]-3-[(1-formamido-1H)-tetrazol-5-yl)thiomethyl]-3-cephem-4-carboxylic acid were obtained as pale brown powder.

1. stirringAfter the mixture was stirred at the same temperature for 10 minutes
2. stirringThen, the mixture was stirred at -18° for 3 hours
3. customAfter the reaction
4. customthe mixture was evaporated under reduced pressure
5. customto remove solvent
6. additionWater was added to the residue
7. washthe aqueous solution was washed with ethyl acetate
8. extractionextracted twice with a mixture of 20 ml of ethyl acetate and 5 ml of tetrahydrofuran
9. washwashed with water
10. customdried
11. customevaporated under reduced pressure
12. customto remove solvent
13. additionEther was added to the residue
14. customthus obtained

ORD record

ord-2838c890f1a948db9ec97cbd9a72c1b0

Source dataset

uspto-grants-1986_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04576938