Method for the preparation of biphephos
View Patent ↗The invention relates to a process for producing 6,6′-[(3,3′-di-tert-butyl-5,5′-dimethoxy-1,1′-biphenyl-2,2′diyl)bis(oxy)]bis(dibenzo[d,f][1,3,2]dioxaphosphepine), abbreviated to biphephos (see formula 1), with low chlorine content.
1. A process for producing biphephos, the process comprising:
reacting 3,3′-tert-butyl-2,2′-dihydroxy-5,5′ dimethoxybiphenyl with 6-chlorodibenzo[d,f][1,3,2]dioxaphosphepine in the presence of a base and a solvent mixture comprising acetonitrile;
wherein:
the reaction provides a biphephos product having a total chlorine content of less than 5000 ppm; and
the reaction provides a biphephos yield of greater than 80%.
2. The process according to claim 1 , wherein the solvent mixture comprises at least 40% by weight of acetonitrile.
3. The process according to claim 1 , wherein the solvent mixture further comprises up to 60% by weight of at least one solvent different from acetonitrile.
4. The process according to claim 3 , wherein the at least one solvent different from acetonitrile is selected from the group consisting of toluene, ortho-xylene, n-heptane, ethyl acetate, and propylene carbonate.
5. The process according to claim 1 , wherein the reacting takes place in a temperature range from above a crystallization temperature of a eutectic mixture of water and sodium chloride up to +10° C.
6. The process according to claim 5 , wherein the reacting takes place in a temperature range from above −10° C. to +5° C.
7. The process according to claim 1 , further comprising:
isolating a resultant solid after the reacting.
8. The process according to claim 1 , further comprising, after the reacting and optional isolating:
dissolving a solid mainly comprising biphephos in an acetonitrile-free solvent or solvent mixture,
removing insoluble constituents by filtration,
crystallizing or precipitating biphephos via cooling of the acetonitrile-free solvent or solvent mixture, and
isolating the biphephos.
9. The process according to claim 2 , wherein the solvent mixture comprises at least 80% by weight of acetonitrile.
10. The process according to claim 3 , wherein the solvent mixture further comprises up to 20% by weight of the at least one solvent different from acetonitrile.
11. The process according to claim 10 , wherein the at least one solvent different from acetonitrile is selected from the group consisting of toluene, ortho-xylene, n-heptane, ethyl acetate, and propylene carbonate.
12. The process according to claim 1 , wherein the base is pyridine.
13. The process according to claim 8 , wherein the isolating the solid comprises filtering.
14. The process according to claim 13 , further comprising:
drying the solid.
15. The process according to claim 10 , wherein isolating the biphephos comprises filtering.
16. The process according to claim 15 , further comprising drying the biphephos obtained by filtration.
17. The process according to claim 13 , further comprising: re-slurrying the solid obtained by filtration in a solvent.
18. The process according to claim 17 , further comprising: repeating the re-slurrying in the solvent or a different solvent.
19. The process according to claim 17 , further comprising: drying the solid obtained by filtration.