was then stirred for an additional 34 minutes yielding a dichlorophosphine reaction product 2 having a 31 p nmr chemical shift of 174 28 ppm to this solution imidazole 51 34 g 0 753 mol in tetrahydrofuran 243 ml was added while stirring and maintaining an internal temperature of 7 8 u00b0 c to 3 6 u00b0 c for 37 minutes the resulting mixture was then stirred for an additional 20 minutes yielding a solution of a bis amino phosphino reaction product 3 having a 31 p nmr chemical shift of 106 36 ppm to this mixture was added a solution consisting of 2 r hydroxymethyldiethylenetriamine pentaacetic acid penta t butyl ester 4 160 0 g 0 128 mol purity 56 32 by weight in heptane 114 ml while stirring and maintaining an internal temperature of 6 8 u00b0 c to 4 8 u00b0 c for 1 hour and 6 minutes this mixture was then stirred for an additional 23 minutes yielding a solution 5 having a 31 p nmr chemical shift of 123 8 ppm finally water 202 ml was added over a period of about 1 minute while maintaining an internal temperature of 6 5 u00b0 c to 6 5 u00b0 c the mixture was stirred for 5 minutes followed by the addition of heptane 620 ml toluene 70 ml and 5n aqueous hydrochloric acid 202 ml over 5 minutes while maintaining.