Sterically hindered 4-amino-piperidine with a low dimer content, its production and use

US6013803A · kind A · utility

Assignee

• BASF SE

Inventors

• Manfred Julius · Schifferstadt, DE
• Harald Rust · Bochum, DE
• Alfred Krause · Speyer, DE
• Hardo Siegel · Speyer, DE
• Wolfgang Siegel · Schifferstadt, DE
• Tom Witzel · Ludwigshafen, DE

Key dates

• Filing date: Nov 12, 1998
• Grant date: Jan 11, 2000
• Expiry date: Nov 12, 2018

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D211/58
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The invention relates to a process for reducing the dimerization of piperidines of the formula I ##STR1## where R.sup.1 to R.sup.4 are C.sub.1 - to C.sub.6 -alkyl, R.sup.1 and R.sup.2 and/or R.sup.3 and R.sup.4 together are a CH.sub.2 chain having 2 to 5 carbon atoms, which comprises adding to the piperidine from 0.001 to 0.2% by weight of a reducing agent of the formula MXH.sub.4-m Y.sub.m, where M is an alkali metal, NR.sub.4, where R are identical or different C.sub.1 -C.sub.4 -alkyl groups, or an equivalent of an alkaline earth metal or an equivalent of zinc, X is boron or aluminum, Y is H or CN and m is 0 or 1. The invention also relates to a mixture of piperidines of the formula I, from 0.001 to 0.2% by weight of a reducing agent and from 1 to 1000 ppm of dimers of the piperidines of the formula I, and to the preparation of hindered amine light stabilizers therefrom.