Process for the preparation of lithium diarylphosphides and alkylated derivatives thereof

Process for the preparation of a triorganophosphine having the formula ##STR18## which comprises the steps of:

• (1) contacting a triarylphosphine having the formula ##STR19## with lithium and a primary or secondary amine having the formula ##STR20## wherein R.sup.5 is hydrogen or alkyl of up to about 12 carbon atoms and R.sup.6 is alkyl of up to about 12 carbon atoms, at a temperature of about 0.degree. to 30.degree. C. in the presence of tetrahydrofuran solvent, wherein the amount of lithium employed is about 2.2 to 1.8 moles lithium per mole of the triarylphosphine, R.sup.1 is tolyl and R.sup.2 and R.sup.3 independently are selected from phenyl and tolyl;
• (2) contacting the intermediate product solution of step (1) with a secondary or tertiary alkyl halide having a total of about 3 to 8 carbon atoms and the formula ##STR21## wherein R.sup.7 and R.sup.8 are independently selected from alkyl groups containing up to about 4 carbon atoms, R.sup.9 is hydrogen or alkyl containing up to about 4 carbon atoms, and X ischloro or bromo;
• at a temperature of 20.degree. to 40.degree. C.;
• and
• (3) contacting the product solution of step (2) with an alkylating agent having the formula ##STR22## wherein R.sup.10 is alkyl of up to 6 carbon atoms or cycloalkyl;
• R.sup.11 is a chemical bond or an organic divalent linking group;
• and Z represents a nucleophilic leaving group.

Process for the preparation of a triorganophosphine having the formula ##STR23## which comprises the steps of:

• (1) contacting a triarylphosphine having the formula ##STR24## with lithium or a primary or secondary amine having the formula ##STR25## wherein R.sup.5 is hydrogen or alkyl of up to about 12 carbon atoms and R.sup.6 is alkyl of up to about 12 carbon atoms, at a temperature of about 0.degree. to 30.degree. C. in the presence of tetrahydrofuran solvent, wherein the amount of lithium employed is about 2.2 to 1.8 moles lithium per mole of the triarylphosphine, R.sup.1 is tolyl and R.sup.2 and R.sup.3 independently are selected from phenyl and tolyl;
• (2) contacting the intermediate product solution of step (1) with a secondary or tertiary alkyl halide having a total of about 3 to 8 carbon atoms and the general formula ##STR26## wherein R.sup.7 and R.sup.8 are independently selected from alkyl groups containing up to about 4 carbon atoms, R.sup.9 is hydrogen or alkyl containing up to about 4 carbon atoms, and X is chloro or bromo;
• at a temperature of 20.degree. to 40.degree. C.;
• and
• (3) contacting the product solution of step (2) with an alkylating agent having the formula ##STR27## wherein R.sup.10 is alkyl of up to 6 carbon atoms or cycloalkyl;
• R.sup.11 is a chemical bond or an organic divalent linking group selected from alkylene of 2 to 20 carbon atoms or a biarylene radical having the formula --Ar--Ar-- wherein each Ar is independently selected from phenylene and naphthylene;
• and Z represents chloro or bromo.