Patent ID: 8536211

Claim:
A process for the preparation of a 5-substituted 1-alkyltetrazole of the formula (I) in which R 1 is selected from the group consisting of (A) alkyl and (B) phenyl optionally monosubstituted by a member selected from the group consisting of halogen, cyano, nitro, C 1 -C 8 -alkyl, C 1 -C 8 -alkoxy, methylsulphonyl, trifluoromethyl and aryl, R 2 is selected from the group consisting of C 1 -C 12 -alkyl, C 1 -C 12 -haloalkyl and an alkoxyalkyl of the formula -[A-O] m —B, wherein A is C 2 -C 4 -alkanediyl (alkylene), B is C 1 -C 6 -alkyl, and m is 1 or 2, comprising the steps of: (1) reacting an acid halide of the formula (II) in which X is halogen, with an alkyl isocyanide of the formula (III) R 2 —NC (III) to form an imine of the formula (IV) (2) and then reacting the imine (IV) with an azide of the formula (V) R 3 —N 3 (V) in which R 3 is selected from the group consisting of sodium, potassium, tetrabutylammonium, trimethylsilyl, and diphenylphosphoryl, optionally in the presence of a base, to form the 5-substituted 1-alkyltetrazole of the formula (I).