Process for the preparation of ethane-1,2-diphosphinic acid diesters
AssigneeHoechst Aktiengesellschaft
InventorsHans-Jerg Kleiner, Walter Rupp
Life of this patent
Estimating the term…
Abstract
A process for the preparation of ethane-1,2,-diphosphinic acid diesters of the formula ##STR1## where R.sub.1 represents alkyl, phenyl and/or phenalkyl groups having from 1 to 18 carbon atoms and R.sub.2 alkyl groups having from 1 to 18 carbon atoms, which may be optionally substituted by halogen atoms, which comprises reacting phosphonous acid esters of the formula ##STR2## where R.sub.1 and R.sub.2 are as define above, with acetylene in the presence of catalytic amounts of radical-forming agents and/or with UV irradiation.
Claims5
In a process for the preparation of an ethane-1,2-diphosphonic acid diester of the formula ##STR5## wherein R.sub.1 represents an alkyl, phenyl and/or phenylalkyl group having from 1 to 18 carbon atoms and R.sub.2 is an alkyl group or a halogen substituted alkyl group having from 1 to 18 carbon atoms, by reacting with acetylene a phosphonous acid ester of the formula ##STR6## wherein R.sub.1 and R.sub.2 are as defined above, at a temperature of from 50.degree. to 230.degree. C in the presence of a catalytic amount of a radical-forming agent, the improvement which comprises first heating said phosphonous acid ester to the desired reaction temperature under atmospheric pressure with the exclusion of atmospheric oxygen and then introducing acetylene and simultaneously slowly adding the radical-forming agent dissolved in said phosphonous acid ester.
Dependencies are inferred from the claim text.