Abstract: There are disclosed certain aminoethanethiols, and salts thereof, and certain thiazolidines which are made therefrom. The compounds are useful as intermediates in the synthesis of photographic image dye-providing materials.

Abstract: This invention relates to derivatives of phthalaldehydic and naphthalaldehydic acid useful as intermediates in the preparation of pH-sensitive phthalide and naphthalide indicator dyes.A class of intermediates provided by the present invention comprises compounds of the formula: ##STR1## wherein A represents 4'-hydroxy-1'-naphthyl; B represents 4'-hydroxy-1'-naphthyl or indol-3-yl and C represents a 2-carboxy-1-phenyl radical or an 8-carboxy-1-naphthyl radical and preferably is 8-carboxy-1-naphthyl.

Abstract: This invention relates to derivatives of phthalaldehydic and naphthalaldehydic acid useful as intermediates in the preparation of pH-sensitive phthalide and naphthalide indicator dyes.A class of intermediates provided by the present invention comprises compounds of the formula: ##STR1## wherein A represents 4'-hydroxy-1'-naphthyl; B represents 4'-hydroxy-1'-naphthyl or indol-3-yl and C represents a 2-carboxy-1-phenyl radical or an 8-carboxy-1-naphthyl radical and preferably is 8-carboxy-1-naphthyl.

Abstract: This invention relates to a class of indicator dyes useful as optical filter agents in photographic processes to protect a selectively exposed photosensitive material from further exposure during processing in the presence of incident light. Such dyes comprise 3,3-disubstituted phthalides and 3,3-disubstituted naphthalides wherein one of the 3,3-substituents is an indol-3-yl radical substituted with hydrogen on the heterocyclic N atom and the other of said 3,3 substituents is a p-hydroxycarbocyclic aryl radical selected from a 4'-hydroxy-1'-phenyl radical and a 4'-hydroxy-1'-naphthyl radical.

Abstract: This invention relates to derivatives of phthalaldehydic and naphthalaldehydic acid useful as intermediates in the preparation of pH-sensitive phthalide and naphthalide indicator dyes. One class of intermediates provided by the present invention comprises compounds of the formula: ##SPC1##Wherein A represents 4'-hydroxy-1'-naphthyl and X represents the atoms necessary to complete a ring-closing moiety selected from a phthalide and a naphthalide and preferably is naphthalide.Another class of intermediates provided by the present invention comprises compounds of the formula: ##SPC2##Wherein A represents 4'-hydroxy-1'-naphthyl; B represents 4'-hydroxy-1'-naphthyl or indol-3-yl and C represents a 2-carboxy-1-phenyl radical or an 8-carboxy-1-naphthyl radical and preferably is 8-carboxy-1-naphthyl.