Hoechst Aktiengesellschaft

Hoechstaktiengesellschaft

Georg Schmailzl

Gerhard Pfahler

Gunther Nowy

Karl Gaa

Josef Wiedemann

G Unter Nowy

The invention relates to an environmentally friendly process for the preparation of compounds of the formula below ##STR1## in which R.sup.1 and R.sup.2 are preferably H or alkyl, R.sup.3 and R.sup.4 are preferably alkyl or cycloalkyl, R.sup.5 and R.sup.6 are preferably hydrogen or methyl and R.sup.7 is in particular alkyl. In the process, the additional use of a phase transfer catalyst can be dispensed with without loss in yield.

Process for the preparation of 1-oxa-3,8-diaza-4-oxospiro[4.5]decane

The invention relates to a process for the preparation of polyalkyl-1-oxa-diazaspirodecane compounds, which can be used as highly active light stabilizers for polymers. The reaction is carried out in a solvent mixture of at least one alcohol and if appropriate an inert organic solvent in the presence of solid alkali metal hydroxide or a corresponding amount of a mixture of solid alkali metal hydroxide and water as the sole catalyst. The process offers the advantage that, by using a solvent mixture and dispensing with a phase transfer catalyst, a higher rate of reaction and therefore higher product quality with the same yield are achieved. By dispensing with a phase transfer catalyst, which remains in the waste water and must be disposed of expensively, and by the reusability of the solvent mixture, the process is more environment-friendly and more economical than processes known to date.

Process for the preparation of polyalkyl-1-oxa-diazaspirodecane compounds

In plastic molding compositions, in particular those based on olefin polymers, which contain phenolic stabilizers and metal ions as catalyst residues, the discoloration at the processing temperature is reduced if they contain triglycerol or ditrimethylolpropane as catalyst deactivators.

Process for reducing the discoloration of a plastic molding composition

Novel polymeric polyalkyl-1-oxa-diazaspirodecanes of the formula I ##STR1## are very effective stabilizers for natural any synthetic polymers. They have very low volatility, high migration resistance and high thermal stability.

Polymeric polyalkyl-1-oxa-diazaspirodecanes

By dividing the known condensation of acetoacetic acid diol esters with phenols into two process steps, a reduction in the cost of the entire process can be achieved. Methyl acetoacetate is first condensed with a phenol and the methyl 3,3-bis(4-hydroxyalkylphenyl)butanoate formed is reacted with the desired diol in the presence of a transesterification catalyst. In this way only one acetoacetic ester is necessary for various final products. The final products are useful stabilizers for plastics, in particular polyolefins.

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Gersthofen, Germany

Georg Schmailzl