Process for preparing alkanediols

Details Process for preparing alkanediols Process for preparing alkanediols

1996-03-20

2001-01-30

Cook, Rebecca (Department: 1205)

Organic compounds -- part of the class 532-570 series

Organic compounds

Oxygen containing

C568S483000

Reexamination Certificate

active

06180838

ABSTRACT:

BACKGROUND OF THE INVENTION
This invention relates to the preparation of alkanediols including 1,3-propanediol. In a specific aspect, the invention relates to a rhodium-catalyzed process for manufacturing 1,3-propanediol in high yields without the use of a phosphine ligand for the rhodium catalyst.
1,3-propanediol (PDO) is an intermediate in the production of polyesters for fibers and films. It is known to prepare PDO in a two-step process involving (1) the rhodium-catalyzed hydroformylation (reaction with synthesis gas, H
2
/CO) of ethylene oxide to intermediate 3-hydroxypropanal (HPA) and (2) hydrogenation of the HPA to PDO. The initial hydroformylation step can be carried out at temperatures greater than 100° C. and at high syngas pressures to achieve practical reaction rates. The resulting product mixture is, however, rather unselective for HPA.
In an alternate hydroformylation method, the rhodium catalyst is used in combination with a phosphine ligand to prepare HPA with greater selectivity and at lower temperature and pressure. However, the use of a phosphine ligand adds to the cost of the catalyst and increases the complexity of catalyst recycle.
It would be desirable to prepare PDO and other alkanediols in a low temperature, selective process which permitted efficient recycle of the rhodium catalyst.
It is therefore an object of the invention to provide a process for the preparation of alkanediols. In a specific embodiment, it is an object of the invention to provide an economical process for the preparation of 1,3-propanediol which does not require the use of a phosphine-ligated rhodium catalyst for preparation of the HPA intermediate.
SUMMARY OF THE INVENTION
According to the invention, an alkanediol is prepared in a process comprising the steps of:
(a) contacting an alkylene oxide with carbon monoxide and hydrogen in an essentially non-water-miscible solvent in the presence of an effective amount of a non-phosphine-ligated rhodium catalyst and an effective amount of a catalyst promoter at a temperature within the range of about 90 to about 125° C. and a pressure within the range of about 15 to about 5000 psig, under reaction conditions effective to produce an intermediate product mixture comprising less than 15 wt % hydroxyaldehyde;
(b) adding an aqueous liquid to said intermediate product mixture and extracting into said aqueous liquid at a temperature less than about 125° C. a major portion of the hydroxyaldehyde to provide an aqueous phase comprising hydroxyaldehyde in greater concentration than the concentration of hydroxyaldehyde in said intermediate product mixture, and an organic phase comprising at least a portion of the rhodium catalyst or a rhodium-containing derivative thereof;
(c) separating the aqueous phase from the organic phase;
(d) contacting the aqueous phase comprising hydroxyaldehyde with hydrogen in the presence of a hydrogenation catalyst at a pressure of at least about 100 psig and a temperature during at least a portion of the hydrogenation step of at least 40° C. to provide a hydrogenation product mixture comprising an alkanediol; and
(e) recovering the alkanediol from said hydrogenation product mixture.
The process enables the production of alkanediols such as 1,3-propanediol in high yields and selectivity without the use of a phosphine-ligated rhodium catalyst in the hydroformylation step.


REFERENCES:
patent: 3687981 (1972-08-01), Lawrence
patent: 4873379 (1989-10-01), Murphy
patent: 4935554 (1990-06-01), Murphy et al.
patent: 4973741 (1990-11-01), Beavers
patent: 5030766 (1991-07-01), Briggs
patent: 5043480 (1991-08-01), Beavers
patent: 5053562 (1991-10-01), Tau
patent: 5135901 (1992-08-01), Beavers
patent: 5210318 (1993-05-01), Briggs
patent: 5225387 (1993-07-01), Briggs
patent: 5256827 (1993-10-01), Slaugh
patent: 5426249 (1995-06-01), Haas et al.
patent: 5463146 (1995-10-01), Slaugh et al.

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