Cefmenoxime

Cefmenoxime is a third-generation cephalosporin antibiotic.^[1]

Cefmenoxime

Clinical data
AHFS/Drugs.com	International Drug Names
Routes of administration	Intramuscular, intravenous
ATC code	J01DD05 (WHO) S01AA31 (WHO), S02AA18 (WHO)
Pharmacokinetic data
Bioavailability	100% (given IM)
Protein binding	50% to 70%
Metabolism	Negligible
Elimination half-life	1 hour
Excretion	Kidney, unchanged
Identifiers
IUPAC name (6R,7R)-7-{[(2E)-2-(2-amino-1,3-thiazol-4-yl)- 2-methoxyimino-acetyl]amino}-3-[(1-methyltetrazol- 5-yl)sulfanylmethyl]-8-oxo-5-thia-1-azabicyclo[4.2.0] oct-2-ene-2-carboxylic acid
CAS Number	65085-01-0 Y
PubChem CID	9570757
DrugBank	DB00267 Y
ChemSpider	7845223 Y
UNII	KBZ4844CXN
KEGG	D07641 Y
ChEBI	CHEBI:55490 Y
ChEMBL	ChEMBL1201224 N
CompTox Dashboard (EPA)	DTXSID2022755
Chemical and physical data
Formula	C16H17N9O5S3
Molar mass	511.55 g·mol−1
3D model (JSmol)	Interactive image
SMILES O=C2N1/C(=C(\CS[C@@H]1[C@@H]2NC(=O)C(=N\OC)/c3nc(sc3)N)CSc4nnnn4C)C(=O)O
InChI InChI=1S/C16H17N9O5S3/c1-24-16(20-22-23-24)33-4-6-3-31-13-9(12(27)25(13)10(6)14(28)29)19-11(26)8(21-30-2)7-5-32-15(17)18-7/h5,9,13H,3-4H2,1-2H3,(H2,17,18)(H,19,26)(H,28,29)/b21-8-/t9-,13-/m1/s1 Y Key:HJJDBAOLQAWBMH-YCRCPZNHSA-N Y
NY (what is this?)  (verify)

Synthesis

The alkylation of ethyl 2-hydroxyimino-3-oxobutanoate (1) with dimethylsulfate gives ethyl (2Z)-2-methoxyimino-3-oxo-butanoate (2). Halogenation with molecular bromine leads to ethyl 4-bromo-2-methoxyimino-3-oxobutanoate (3). Treatment with thiourea gives ethyl (Z)-2-(2-amino-4-thiazolyl)-2-methoxyiminoacetate (4) which is reacted with chloroacetyl chloride to give the amide (5). Saponification with potassium hydroxide gives (6) which is halogenated with phosphorus pentachloride to (7). Amide formation with the cephalosporin intermediate (8) then gives (9). Removal of the protecting group with benzyltriethylammonium bromide yields (10). The tert-butyl ester was deprotected with trifluoroacetic acid to give (11). Lastly, thioether formation with 5-mercapto-1-methyltetrazole (12) completes the synthesis of cefmenoxime.^[2][3][4][5]