Abstract: In one embodiment, a scale inhibitor comprising at least one polymethylenephosphonate derivative having the following formula: wherein n is a number, wherein M is hydrogen or a cation, wherein R1, R2, and R3 are each independently selected from the group consisting of CH2PO3M2, CH2R4, wherein R4 is CHOHCH3, CHOHCH2Cl, or CHOHCH2OH, (CH2)mSO3M, wherein m is 3 or 4, and CH2CH2R5, wherein R5 is CONH2, CHO, COOR6, COOX, or CN, wherein R6 is CH3 or C2H5, and wherein X is an alkali metal or ammonium, and wherein at least one of R1, R2, and R3 is not CH2PO3M2. In another embodiment, a method for inhibiting scale formation in water, and in still another embodiment, a method for sequestering iron ions in a water systems, each of the methods comprising the step of providing the water with the above described polymethylenephosphonate derivative.

Abstract: A new class of polyaminophosphonate derivatives usable as inhibitors of precipitation and dispersants in aqueous systems. The products in object have complete tolerance of calcium and can be employed in severe conditions of use in the water treatment and detergent fields.

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.