NOVELTY - Preparation of dronedarone (I) and its salts, comprises: reacting N-(2-butyl-3-(4-((3-amino)propoxy)benzoyl)-1-benzofuran-5-yl)-methansulfonamide compound (II) or its salts with butyl compounds (III); and isolating the product obtained, and if desired, converting into its salt.    USE - The process is useful for preparation of dronedarone (claimed) which is useful for treating arrhythmia. No biological data given.    ADVANTAGE - The process provides higher yields of highly pure dronedarone in a simple, economical and environmental friendly manner.    DETAILED DESCRIPTION - Preparation of dronedarone (I) and its salts, comprises: reacting N-(2-butyl-3-(4-((3-amino)propoxy)benzoyl)-1-benzofuran-5-yl)-methansulfonamide compound (II) or its salts with butyl compounds of formula (L-(CH2)3-CH3) (III); and isolating the product obtained, and if desired, converting into its salt.L = leaving group, preferably benzenesulfonyloxy (optionally substituted with halo, alkyl, alkoxy, nitro or protected amino group), halo, methanesulfonyloxy or trifluoromethanesulfonyloxy.    INDEPENDENT CLAIMS are also included for:    (1) the N-(2-butyl-3-(4-((3-amino)propoxy)benzoyl)-1-benzofuran-5-yl)-methansulfonamide compound (II) or its salts;    (2) preparation of (II) or its salts, comprising: hydrogenating the N-(2-butyl-3-(4-(2-cyanoethoxy)benzoyl)-1-benzofuran-5-yl)methanesulfonamide compound (IV) or deprotecting the substituted N-(3-(4-(3-aminopropoxy)benzoyl)-2-butylbenzofuran-5-yl)methanesulfonamide compound of formula (V); and isolating the obtained product, and if desired converting into its salts;    (3) the N-(2-butyl-3-(4-(2-cyanoethoxy)benzoyl)-1-benzofuran-5-yl)methanesulfonamide compound (IV) or its salts;    (4) preparation of (IV) or its salts, comprising: mesylating the compound ((5 amino-2-butyl-benzofur-3-yl)-(4-(2-cyanoethoxy)phenyl)methanone) (VI); and isolating the obtained product, and if desired converting into its salts;    (5) the substituted N-(3-(4-(3-aminopropoxy)benzoyl)-2-butylbenzofuran-5-yl)methanesulfonamide compound of formula (V) or its salts;    (6) preparation of the compound (V) or its salts, comprising: reacting the N-(2-butyl-1-benzofuran-5-yl)methanesulfonamide compound (X) with the substituted 4-(3-aminopropoxy)benzoyl chloride compound of formula (XI) under Friedel-Crafts reaction conditions; and isolating the obtained product, and if desired converting into its salts;    (7) the compound ((5-amino-2-butyl-benzofur-3-yl)-(4-(2-cyanoethoxy)phenyl)methanone) (VI) or its salts;    (8) preparation of compound (VI) or its salts, comprising hydrogenating the (5-nitro-2-butyl-benzofur-3-yl)-(4-(2-cyanoethoxy)phenyl)methanone compound (VII); and isolating the obtained product, and if desired converting into its salts;    (9) the (5-nitro-2-butyl-benzofur-3-yl)-(4-(2-cyanoethoxy)phenyl)methanone compound (VII); and    (10) preparation of the compound (VII) comprising reacting the (2-butyl-5-nitro-1-benzofur-3-yl)-(4-hydroxyphenyl)methanone compound of formula (VIII) with acrylonitrile, and isolating the obtained product.    Pg = amino protecting group.