N-(2-sulpho-arylmethyl)-pyridinium-betaine derivs. prodn. - by reacting N-(aryl-methyl)-pyridinium salt with sulphur tri:oxide in the presence of sulphuric and/or phosphoric acid

摘要

Prodn. of N-(2-sulphoarylmethyl)-pyridinium-betaines of formula (I), (where X is an acid anion; and each R1 and R2 is H, aliphatic gp. or alkoxy, and R1 can each also be halogen and each R2 can also represent an aromatic ring annellated on the pyridine ring), comprises reacting an N-(aryl-methyl)- pyridinium salt of formula (II) with SO3 in the presence of H2SO4 and/or H3PO4. (I) are intermediates in the prepn. of dyestuffs and pesticides. (I) are also polishing and levelling agents for galvanic baths esp. acid galvanic Ni baths. (I) are good levelling agents in both high current density regions and low current density regions, without having too strong a negative effect on the macrodispersibility. (I) can be used in combination with other Ni polishers. (I) can be used as additives in the corrosion protection of steel, brass, Zn, Al alloys and Mg alloys and to give shiny, hard, very ductile and smooth Ni-coatings. (I) can also be used as a levelling agent in dyeing anionic modified polyacrylonitrile fibres. (I) are obtd. in good yields and purity by a simple and economic method.