Salicylic acid derivatives

A process for preparing a salicylic acid derivative represented by the formula (1):

• ##STR10## wherein X.sub.1 and X.sub.2 are a hydrogen atom, an alkyl group, an alkoxy group, an aralkyl group, an aryl group or a halogen atom, Y.sub.1 and Y.sub.2 are an oxygen atom or a sulfur atom, R.sub.1 is a hydrogen atom, an alkyl group, an aralkyl group or an aryl group , and R.sub.2 is an alkyl group, an alkenyl group, an aralkyl group or an aryl group, comprising reacting a compound represented by the formula (2):
• ##STR11## wherein X, X.sub.2 and R.sub.1 are the same as above, with a compound represented by the formula (3):
• ##STR12## wherein Y.sub.1, Y.sub.2 and R.sub.2 are the same as above and Z is a halogen atom, in the presence of an alcohol-based solvent.

A process for preparing a polyvalent metal salt of a salicylic acid derivative represented by the formula (1):

• ##STR13## wherein X.sub.1 and X.sub.2 are a hydrogen atom, an alkyl group, an alkoxy group, an aralkyl group, an aryl group or a halogen atom, Y.sub.1 and Y.sub.2 are an oxygen atom or a sulfur atom, R.sub.1 is a hydrogen atom, an alkyl group, an aralkyl group or an aryl group , and R.sub.2 is an alkyl group, an alkenyl group, an aralkyl group or an aryl group, comprising reacting a compound represented by the formula (2):
• ##STR14## wherein X.sub.1, X.sub.2 and R.sub.1 are the same as above, with a compound represented by the formula (3):
• ##STR15## wherein Y.sub.1, Y.sub.2 and R.sub.2 are the same as above and Z is a halogen atom, in the presence of an alcohol-based solvent, treating the resultant salicylic acid derivative represented by the formula (1) with an alkali metal salt, and carrying out a double decomposition reaction of the resulting alkali metal salt of the salicylic acid derivative in an aqueous solution with a water soluble compound of a metal having from 2 to 4 valence.