Preparation of 4-nitro-5-imidazolyl ethers and thioethers

A process for the preparation of a 4-nitro-5-imidazolyl ether or thioether of the formula ##STR23## where R.sub.1 is C.sub.1 -C.sub.18 -alkyl, C.sub.2 -C.sub.8 -alkoxyalkyl, C.sub.5 -C.sub.8 -cycloalkyl, phenyl or naphthyl, unsubstituted or substituted by C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -alkoxy, halogen, C.sub.1 14 C.sub.4 -haloalkyl or C.sub.1 -C.sub.4 -alkoxymethyl, C.sub.7 -C.sub.12 -aralkyl or C.sub.7 -C.sub.12 -alkylphenyl, R.sup.2 is hydrogen, C.sub.1 -C.sub.18 -alkyl, C.sub.5 -C.sub.8 -cycloalkyl, phenyl or naphthyl, unsubstituted or substituted by C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -alkoxy, halogen, C.sub.1 -C.sub.4 -haloalkyl or C.sub.1 -C.sub.4 -alkoxymethyl, C.sub.7 -C.sub.12 -aralkyl or C.sub.7 -C.sub.12 -alkylphenyl, R.sup.3 is C.sub.1 -C.sub.18 -alkyl, C.sub.2 -C.sub.8 -alkoxyalkyl, C.sub.5 -C.sub.8 -cycloalkyl, phenyl or naphthyl, unsubstituted or substituted by C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -alkoxy, halogen, C.sub.1 -C.sub.4 -haloalkyl or C.sub.1 -C.sub.4 -alkoxymethyl, C.sub.7 -C.sub.12 -aralkyl or C.sub.7 -C.sub. 12 -alkylphenyl, or a saturated, unsaturated, or aromatic 5- or 6-membered heterocyclic with 1 or 2 hetero atoms selected from the group consisting of nitrogen, oxygen and sulfur, or a counter-ion of the corresponding alcoholate or thiolate or, if X is sulfur, R.sup.3 is hydrogen, and X is oxygen or sulfur, and the stated organic radicals may furthermore carry substituents which are inert under the reaction conditions, which process comprises:

• reacting a dinitroimidazole of the formula ##STR24## with an alcohol or thiol of the formula
• R.sup.3 --XH (III)
• in a solvent or diluent selected from the group consisting of water, water-miscible inert organic solvents and mixtures thereof, at a pH of from 4 to 16 and at a temperature of 0.degree. to 150.degree. C.