Abstract: The present invention relates to the preparation of alkyl-ureas, starting from O,S-dimethyl dithiocarbonate, which provides the following steps: A) causing the O,S-dimethyl dithiocarbonate to react with a primary amine of general formula R1NH2 in order to obtain an O-methyl thiocarbamate; B) isomerising the O-methyl thiocarbamate in order to obtain an S-methyl thiocarbamate; C) causing the S-methyl thiocarbamate with a compound of general formula R′R″NH, wherein R′ and R″ may be equal or different one in respect of the other and of R1 and may be H, R2 or R3, in order to obtain one of the alkyl-ureas of formula (4), (5) or (6).

Abstract: Process for the esterification of organic acids with alcohols in a reactor of the chromatographic type in which the heterogeneous solid phase is capable of acting both as an esterification catalyst and as a means exhibiting preferential adsorption towards one of the reaction products (typically water). The process to which the present invention relates is particularly improved compared with conventional technology owing to the use, as the means for regenerating the catalyst, of a desorbent to which has been added a second compound, generally the anhydride of the acid used in the esterification reaction, which, by chemical reaction, completes the removal of the adsorbed water.

Abstract: Process for the esterification of organic acids with alcohols in a reactor of the chromatographic type in which the heterogeneous solid phase is capable of acting both as an esterification catalyst and as a means exhibiting preferential adsorption towards one of the reaction products (typically water). The process to which the present invention relates is particularly improved compared with conventional technology owing to the use, as the means for regenerating the catalyst, of a desorbent to which has been added a second compound, generally the anhydride of the acid used in the esterification reaction, which, by chemical reaction, completes the removal of the adsorbed water.