Oxibendazole

Oxibendazole

Systematic (IUPAC) name
methyl N-(6-propoxy-1H-benzimidazol-2-yl)carbamate
Clinical data
AHFS/Drugs.com	International Drug Names
Legal status	Veterinary use only
Identifiers
CAS Number	20559-55-1 Y
ATCvet code	QP52AC07
PubChem	CID 4622
ChemSpider	4461 N
UNII	022N12KJ0X Y
KEGG	D05293 Y
Chemical data
Formula	C12H15N3O3
Molar mass	249.26 g/mol
SMILES CCCOC1=CC2=C(C=C1)N=C(N2)NC(=O)OC
InChI InChI=1S/C12H15N3O3/c1-3-6-18-8-4-5-9-10(7-8)14-11(13-9)15-12(16)17-2/h4-5,7H,3,6H2,1-2H3,(H2,13,14,15,16) N Key:RAOCRURYZCVHMG-UHFFFAOYSA-N N
NY (what is this?)  (verify)

Oxibendazole is a benzimidazole drug that is used to protect against roundworms, strongyles, threadworms, pinworms and lungworm infestations in horses and some domestic pets. It is usually white to yellowish in appearance, and may take the form of a powder or a tablet.

Synthesis

Oxibendazole synthesis:^[1]

4-Hydroxyacetamide is alkylated with n-propylbromide in the presence of KOH to give the ether (2). Nitration of the product with HNO3/H2SO4 proceeds at the position ortho to the amido group (3); saponification followed by reduction of the nitro group with SnCl₂gives the phenylenediamine (4).

Reaction of that intermediate with S-methylthiourea can be visualized as proceeding first to the guanidine obtained by addition to the imine double bond followed by elimination of methyl mercaptan. Cyclization completes the construction of the 2-aminobenzimidazole system. Acylation with methyl chloroformate results in the formation of a urethane on the amino group to produce 6.

References