Photographic color couplers, photographic materials containing them and method of forming dye images

Claim 2

A photographic element comprising a support and a photographic silver halide emulsion having associated therewith a color coupler which comprises an imidazo[1,2-b]pyrazole nucleus and which reacts at its 3-position with an oxidized aromatic primary amino color developing agent and contains a non-coupling-off group in the 7-position.

Claim 3

A photographic element as in claim 1 wherein said color coupler has the general formula: ##STR39## in which R 1 and R 2 are each hydrogen or a substituted or unsubstituted alkyl, a substituted or unsubstituted aryl, heterocyclic, hydroxy, nitrile, sulfone, acylamido, sulfonamido, sulfamoyl, alkoxycarbonyl, aryloxycarbonyl or nitro group, an amino or substituted amino group, a carbamoyl or substituted carbamoyl group, a non-coupling-off group alkoxy group or a non-coupling-off phenolic stabilizer moiety, R 3 is any of the non-coupling-off groups which R 1 and R 2 represent, and X is hydrogen or a group which splits off during coupling.

Claim 4

A photographic element as in claim 2 wherein X is a halogen, sulfo, carboxy, R 4 --O--, R 4 --S-- wherein R 4 is a substituted or unsubstituted alkyl or aryl group or an amino or substituted amino group or an acyloxy, sulfonyloxy or benzotriazolyl group, or an azo radical rendering the coupler colored.

Claim 5

A photographic element as in claim 2 wherein the group X, when released from the coupler, forms a photographically useful compound.

Claim 6

A photographic element as in claim 2 wherein the group X, when released from the coupler, forms a photographically useful compound which is a development inhibitor.

Claim 7

A photographic element as in claim 2 wherein R 1 , R 2 and R 3 represent a straight or branched chain alkyl group having 1-22 carbon atoms.

Claim 8

A process of forming a dye image in an exposed photographic element comprising a support and a photographic silver halide emulsion, said process comprising developing the photographic element with a silver halide color developing agent in the presence of a color coupler which comprises an imidazo-[1,2-b]pyrazole nucleus and which reacts at its 3-position with an oxidized aromatic primary amino color developing agent and said coupler contains a non-coupling-off group in the 7-position.

Claim 9

A process of forming a dye image in an exposed photographic element comprising a support and a photographic silver halide emulsion, said process comprising developing the photographic element with a silver halide color developing agent in the presence of a color coupler which comprises an imidazo-[1,2-b]pyrazole nucleus and which reacts at its 3-position with an oxidized aromatic primary amino color developing agent and said coupler contains a non-coupling-off group in the 7-position.

Claim 10

A process as in claim 7 wherein the color developing agent is a p-phenylenediamine.

Claim 11

A photographic element comprising a support and a photographic silver halide emulsion having associated therewith a color coupler selected from the group consisting of: ______________________________________ ##STR40## Coupler No. X R1 R2 R3 ______________________________________ 1 H ##STR41## t-Bu CO.sub.2 Et 2 H H t-Bu CN 3 H H t-Bu CONH.sub.2 4 H H t-Bu CO.sub.2 Et 5 OPh ##STR42## t-Bu CO.sub.2 Et ______________________________________

Claim 12

A photographic element comprising a support and a photographic silver halide emulsion having associated therewith a color coupler selected from the group consisting of: ______________________________________ ##STR40## Coupler No. X R1 R2 R3 ______________________________________ 1 H ##STR41## t-Bu CO.sub.2 Et 2 H H t-Bu CN 3 H H t-Bu CONH.sub.2 4 H H t-Bu CO.sub.2 Et 5 OPh ##STR42## t-Bu CO.sub.2 Et ______________________________________