Process for the preparation of 5-substituted 1-alkyltetrazolyl oxime derivatives

A process for the preparation of 5-substituted 1-alkyltetrazolyl oxime derivatives of the general formula (I)

• in which
• R1 is alkyl, or phenyl optionally monosubstituted by halogen, cyano, nitro, C1-C8-alkyl, C1-C8-alkoxy, methylsulphonyl, trifluoromethyl or aryl,
• R2 is C1-C12-alkyl, C1-C12-haloalkyl or an alkoxyalkyl of the formula -[A-O]m-B,
• A is C2 C4-alkanediyl (alkylene),
• B is C1-C6-alkyl,
• m is 1 or 2,
• R3 is a pyridinyl group (Het1) or a thiazolyl group (Het2)
• in which
• R is hydrogen or halogen,
• Z is hydrogen, halogen, in each case substituted or unsubstituted C1-C8-alkyl, C3-C8-cycloalkyl, C2-C8-alkenyl, C2-C8-alkynyl, or the group —N(Ra)C(═O)Q,
• Q is hydrogen, in each case substituted or unsubstituted C1-C8-alkyl, C3-C8-cycloalkyl, C3-C8-cycloalkenyl-C1-C8-alkyl, C3-C8-halocycloalkyl having 1 to 5 halogen atoms, C3-C8-cycloalkyl-C1-C8-alkyl, C3-C8-cycloalkenyl, C2-C8-alkenyl, C2-C8-haloalkenyl having 1 to 5 halogen atoms, C2-C8-alkynyl, C2-C8-haloalkynyl having 1 to 5 halogen atoms, C1-C8alkoxy, C1-C8-haloalkoxy having 1 to 5 halogen atoms, C1-C8-haloalkoxyalkyl having 1 to 5 halogen atoms, C2-C8-alkenyloxy, C2-C8-haloalkenyloxy having 1 to 5 halogen atoms, C3-C8-alkynyloxy, C3-C8-haloalkynyloxy having 1 to 5 halogen atoms, C1-C8-alkylamino, (C1-C6-alkoxyimino)-C1-C6-alkyl, (C1-C6-alkenyloxyimino)-C1-C6-alkyl, (C1-C6-alkinyloxyimino)-C1-C6-alkyl, (benzyloxyimino)-C1-C6-alkyl, C1-C8-alkylsulphenyl, arylsulphenyl, tri-(C1-C8-alkyl)silyl-C1-C8-alkyl, tri(C1-C8-alkyl)silyloxy, tri(C1-C8-alkyl)silyl-C3-C8-cycloalkyl, aryl, phenoxy, phenoxyalkyl, benzyloxy, heterocyclyl, C5-C12-bicycloalkyl, C5-C12-bicycloalkenyl, benzo-fused C5-C12-carbocyclyl,
• Ra is hydrogen, in each case substituted or unsubstituted C1-C8-alkyl, C3-C8-cycloalkyl, C2-C8-alkenyl, C2-C8-alkynyl, aryl, heterocyclyl,
• the process comprising the steps of:
• (1) in a first step, converting an oxime of the general formula (II)
• in which R1 has the meanings given above,
• by using a base, to the salt of the oxime, which is then reacted with a compound of the general formula (III)
• in which
• R3 has the meanings given above and
• Y is chlorine, bromine, iodine, mesylate or tosylate,
• (2) in a second step, reacting oxime ethers of the general formula (IV) obtained in the first step
• in which R1 and R3 have the meanings given above,
• with an azide of the formula R5—N3, in which R5 is sodium, potassium, tetrabutylammonium, trimethylsilyl or diphenylphosphoryl, and
• in a third step, reacting 5-substituted tetrazolyl oxime derivatives of the formula (V) obtained in the second step
• in which R1 and R3 have the meanings given above,
• with an alkylating agent of the formula (VI)
• R2-L (VI)
• in which
• R2 has the meanings given above and
• L is halogen or an activated hydroxy compound.