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: A process to prepare alkansulphonamides of formula RSO.sub.2 NR.sup.1 R.sub.2 --wherein R is an alkyl group containing from 1 to 15 carbon atoms, or an alkyl group containing from 1 to 15 carbon atoms substituted by one or more chlorine or bromine atoms, and R.sup.1 and R.sup.2 are equal or different and may be hydrogen or an alkyl group containing from 1 to 15 carbon atoms--provides to treat an alkansulphonylhalide of formula RSO.sub.2 X--wherein X is chlorine, bromine or iodine--with a suitable quantity of a compound of formula NHR.sup.1 R.sup.2, using as solvent for said treatment an aliphatic nitrile.