Patent AT-E399788-T1: [Translated] METHOD FOR PRODUCING 9,10-DIHYDRO-9-OXA-10-ORGANYL-PHOSPHAPHENANTHRENE-10-OXIDE AND DERIVATIVES THEREOF

Preparation of 9,10-dihydro-9-oxa-10-organylphosphaphenanthrene-10-oxide comprises reacting 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide with a mono- or polyhydric alcohol and an ortho ester to form a first intermediate. The first intermediate is reacted with another mono- or polyhydric alcohol to form a second intermediate which is converted to the product using an alkylation agent. An independent claim is also included for a process for the preparation of a natural product or plastic having flame-retardant properties, comprising the inventive preparation process, and introducing the second intermediate product into the natural product or plastic.