Novel hydroquinone derivatives for use as photographic developing agents

摘要

The invention comprises compounds of the general formula wherein each of X, Y and Z is hydrogen, an alkyl group, a hydroxyl group, an aryl group, a halogen atom, a heterocyclic group, or a phenyltetrazolylthio group, or X and Y are carbon atoms forming part of another carbocyclic ring, R is an aryl or alkyl group and R1 is hydrogen or an acetyl group or haloacetyl group. Preferred compounds of Formula II with R1 being hydrogen are those in which (i) each alkyl group which constitutes one of the groups X, Y and Z contains a maximum of 20 carbon atoms; (ii) an alkyl group which constitutes the group R contains a maximum of 5 carbon atoms; (iii) each aryl group which constitutes one of the groups X, Y, Z and R is a phenyl, tolyl or xylyl group; (iv) each heterocyclic group which constitutes one of the groups X, Y and Z is a tetrazolyl, thiazolyl or quinolinyl group. Compounds of the above formula in which R1 is an acetyl group yield the corresponding compounds in which R1 is a hydrogen atom in alkaline solution. The compounds of the above formula in which R1 is hydrogen, may be prepared by reacting a quinone of the formula with a tetrazolylthiol of the structure and those compounds in which R1 is an acetyl or haloacetyl group can be prepared by reacting the compounds in which R1 is hydrogen with acetyl or haloacetyl halide or anhydride. An example is given for the preparation of 1 - phenyl - 5 - tetraazolyl - thio - hydroquinone. The compounds of Formula II are useful for use in photographic development processes (see Division G2).