Abstract: An improved method of producing keto acids having the formula (I), wherein R1 and R2 independently represent (a) hydrogen, 1

Abstract: A heat sensitive recording material, comprising a) at least one colour forming compound, and b) at least one developer of the formula  wherein R1 is unsubstituted or substituted phenyl, naphthyl or C1-C20alkyl, X is a group of the formula A is unsubstituted or substituted phenylene, naphthylene or C1-C12alkylene, or is an unsubstituted or substituted heterocyclic group, B is a linking group of formula —O—SO2—, —SO2—O—, —NH—SO2—, —SO2—NH—, —S—SO2—, —O—CO—, —O—CO—NH—, —NH—CO—, —NH—CO—O—, —S—CO—NH—, —S—CS—NH—, —CO—NH—SO2—, —O—CO—NH—SO2—, —NH═CH—, —CO—NH—CO—, —S—, —CO—, —O—, —SO2—NH—CO—, —O&m

Abstract: Disclosed are a novel crystal form of the fluoran compound represented by formula (I) as characterised by specific X-ray powder diffraction pattern and melting range; process for the preparation of said novel crystal form and recording materials comprising the said crystal form.

Abstract: The invention provides a process for the preparation of 3-(N,N-dimethylamino)benzoic acid which comprises subjecting an aqueous solution of an alkali metal salt or ammonium salt of 3-aminobenzoic acid to reductive methylation in the presence of a supported transition metal catalyst, by the controlled and continuous addition of a solution of formaldehyde over a period of 0.5 to 20 hours with a hydrogen pressure between 1 bar and 40 bar and with the temperature of the reaction mass gradually raised during the reduction, the reaction being carried out within the temperature range of 20.degree. C. to 120.degree. C., and wherein a buffering agent is added such that the pH of the reaction mass after reductive methylation is from 6.5 to 9.5.

Abstract: A method for the purification of a keto acid having the general formula ##STR1## wherein R1 and R2 independently represent a straight or branched chain alkyl of 1-18 carbon atoms, a cycloalkyl of 4-8 carbon atoms or a phenyl both of which may be substituted by at least one substituent selected from the group consisting of halogen atoms and alkyls having 1-4 carbon atoms, an aralkyl of 7-10 carbon atoms, alkoxyalkyl having 2-20 carbon atoms, tetrahydrofuryl alkyl, alkylcarboxy alkyl, alkyl carboxy benzyl, or R1 and R2 together with the adjacent nitrogen atom may form a heterocyclic ring, or one of R.sub.1 and R.sub.2 is hydrogen, which comprises slurrying the keto acid with an alcohol solvent, maintaining the slurry at elevated temperature in a sealed vessel until the Rhodamine impurity has dissolved, cooling and isolating the pure keto acid by filtration.

Abstract: A method of producing N,N-disubstituted aminophenols of the general formula ##STR1## wherein R.sub.1 and R.sub.2 are the same or different and each represents a saturated or unsaturated aliphatic hydrocarbyl, cycloalkyl, aralkyl, the phenyl ring of which may be further substituted, alkoxyalkyl, or a cycloalkylalkyl, except that R.sub.1 and R.sub.2 are not simultaneously methyl and R' represents hydrogen, halogen, nitro, cyano, alkyl or alkoxy, which comprises reacting an aminophenol of general formula ##STR2## wherein R.sub.3 represents hydrogen or R.sub.1, and R' is as defined above, with an organic halide species of general formula R.sub.2 X wherein R.sub.2 is as defined above and X is halogen under aqueous acidic conditions with the periodic addition of an acid trapping agent in such a way that continuous monitoring of pH is not required.

Abstract: Pressure-sensitive copying material containing included in its Color-reactant system a mixture of at least two color formers, wherein at least one color former is a leuco methylene dyestuff of the formula ##EQU1## wherein Y represents an amino-substituted phenyl residue of the formula ##SPC1##Or an indolyl residue of the formula ##SPC2##Wherein R.sub.1 and R.sub.2, independently of the other represent hydrogen, alkyl with 1 to 12 carbon atoms, alkoxyalkyl with 2 to 8 carbon atoms, benzyl or phenyl, R.sub.3 is hydrogen, halogen, nitro, alkyl having 1 to 4 carbon atoms or alkoxy having 1 to 4 carbon atoms, X.sub.1 represents hydrogen, alkyl with 1 to 12 carbon atoms, alkenyl with at most 12 carbon atoms or benzyl, X.sub.