Patent GB-569089-A (GB)
Title: Improvements in and relating to colour-forming developers and processes of colour development
IPC: G03C7/34
Filed: 1943-10-29
Abstract: Cis - g  - phenyl - g  - (a  - furyl) - itaconic - b  - ester acid is prepared by adding a mixture of phenylfurylketone and diethyl succinate to a warm solution obtained by adding sodium to absolute alcohol, extracting the precipitated oil with ether and acidifying the residual alkaline solution.  6-Carbethoxy - 4 - acetoxy - 7 - phenylcoumarone is prepared by boiling gently together cis-g -phenyl-g -(a -furyl) - itaconic - b  - ester acid, anhydrous sodium acetate, and acetic anhydride.  4 - Hydroxy - 6 - carbethoxy-7-phenylcoumarone is prepared by adding an excess of warm 5 per cent aqueous caustic soda to a spirit solution of 6-carbethoxy-4-acetoxy - 7 - phenylcoumarone and then acidifying. p 4 - Hydroxy - 6 - carboxy - 7 - phenylcoumarone is prepared by boiling a spirit solution of 4-hydroxy - 6 - carbethoxy - 7 - phenylcoumarone with 4 per cent aqueous caustic potash and acidifying.  6 - Carboxy - 4 - acetoxy - 7 - phenylcoumarone is prepared by warming 4-hydroxy-6-carboxy-7-phenylcoumarone with acetic anhydride and sodium acetate.  2-Acetoxy-9-keto-31 : 21 : 3 : 4-furanofluorene is prepared by dissolving 4-hydroxy-6-carboxy-7-phenylcoumarone in ice-cold concentrated sulphuric acid, allowing to stand, pouring into ice water and acetylating.  The 2 : 4-dinitrophenylhydrazone is referred to. 2-Hydroxy-9-keto-31 : 21 : 3 : 4-furanofluorene is prepared by warming 2 - acetoxy - 9 - keto - 31 : 21 : 3 : 4-furanofluorene with excess aqueous-alcoholic sodium hydroxide.  4 - Acetoxy - 7 - phenylcoumarone-6-carboxylic acid chloride is prepared by reacting 6-carboxy-4 - acetoxy - 7 - phenylcoumarone with thionyl chloride.  4 - Acetoxy - 7 - phenylcoumarone-6-carboxylic acid anhydride is similarly prepared using acetyl chloride.  2-Acetoxy-9-keto-31 : 21 : 3 : 4-furanofluorene is also prepared by warming a carbon disulphide solution of either 4-acetoxy-7-phenylcoumarone-6-carboxylic acid chloride or the corresponding anhydride with aluminium chloride.  Cis - g  - phenyl - g  - (a  - furyl) - itaconic acid is prepared by boiling cis-g -phenyl-g -(a -furyl)-itaconic-b -ester acid with aqueous potassium hydroxide.  3 - Keto - 1 - (a  - furyl) - indene - 2 - acetic acid is prepared by reacting cis-g -phenyl-g -(a -furyl)-itaconic acid with cold concentrated sulphuric acid. 2-Acetoxy-9-keto-31 : 2 : 3 : 4-furanofluorene is also prepared by heating 3-keto-1-(a -furyl)-indene-2-acetic acid with acetic anhydride and anhydrous sodium acetate.  2-Methoxy-9-keto-3 : 4-benzfluorene is prepared by methylating 2-hydroxy-9-keto-3 : 4-benzfluorene dissolved in caustic soda solution with dimethyl-sulphate.  2-Methoxy-9-keto-31 : 21 : 3 : 4-furanofluorene is similarly prepared.  2-Methoxy-3 : 4-benzfluorene is prepared by reducing 2-methoxy-9-keto-3 : 4-benzfluorene by heating in a sealed tube with hydrazine hydrate and methanol.  2 - Methoxy - 31 : 21 : 3 : 4 - furanofluorene is similarly prepared.  2-Hydroxy-3 : 4-benzfluorene is prepared by demethylating 2-methoxy-3 : 4-benzfluorene by heating in acetic acid solution thereof with hydriodic acid.  2-Hydroxy-31 : 21 : 3 : 4-furanofluorene is similarly prepared.  2 : 9-Dihydroxy-3 : 4-benzfluorene is prepared by reducing a caustic soda solution of 2-hydroxy-9 - keto - 3 : 4 - benzfluorene by hydrogenation, using a palladium-carbon catalyst. 2 : 9-Dihydroxy-31 : 21 : 3 : 4-furanofluorene is similarly prepared. Specifications 427,472, 427,516, 427,518, 427,520, 440,032, 440,089, 447,092, 507,841, 524,154, 524,554, 524,555, and 541,589, [all in Group XX], are referred to.