Method for the preparation of chloroformate compositions
First Claim
1. A method for preparing chloroformate compositions which comprises passing phosgene into a heterogeneous mixture of a substantially inert organic liquid and a hydroxy compound of the formula
wherein R2 is an aliphatic or alicyclic radical free from acetylenic unsaturation or an aromatic radical and x is at least 1, said mixture being maintained at a temperature within the range of about 10°
-40°
C., with the proviso that the phosgene addition rate is high enough to effect rapid and complete reaction of phosgene with dissolved hydroxy compound when x is greater than 1 and the temperature is above 30°
C., and simultaneously introducing a hydrogen chloride scavenger comprising an aqueous alkali metal or alkaline earth metal hydroxide solution as necessary while maintaining a pH in the range of 0.5-8 in the aqueous phase;
the ratio of equivalents of total phosgene used to hydroxy compound being about 1.0-1.1;
1.
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Accused Products
Abstract
Chloroformate compositions, particularly bischloroformate compositions, are prepared by the reaction of phosgene with a hydroxy compound, preferably a dihydroxy compound such as bisphenol A, in a heterogeneous mixture, while adding a hydrogen chloride scavenger comprising aqueous base as necessary and maintaining a pH of 0.5-8 during the phosgene addition. When a polyhydroxy compound is employed and the temperature is above 30° C., the phosgene addition rate is maintained at a level high enough to effect rapid and complete reaction with dissolved hydroxy compound. This method uses substantially less phosgene than methods involving a higher pH.
73 Citations
10 Claims
- 1. A method for preparing chloroformate compositions which comprises passing phosgene into a heterogeneous mixture of a substantially inert organic liquid and a hydroxy compound of the formula
- space="preserve" listing-type="equation">R.sup.2 (OH).sub.x, (III)
wherein R2 is an aliphatic or alicyclic radical free from acetylenic unsaturation or an aromatic radical and x is at least 1, said mixture being maintained at a temperature within the range of about 10°
-40°
C., with the proviso that the phosgene addition rate is high enough to effect rapid and complete reaction of phosgene with dissolved hydroxy compound when x is greater than 1 and the temperature is above 30°
C., and simultaneously introducing a hydrogen chloride scavenger comprising an aqueous alkali metal or alkaline earth metal hydroxide solution as necessary while maintaining a pH in the range of 0.5-8 in the aqueous phase;
the ratio of equivalents of total phosgene used to hydroxy compound being about 1.0-1.1;
1.- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
- 6. A method according to claim 5 wherein each of A1 and A2 is p-phenylene.
- 7. A method according to claim 6 wherein Y is isopropylidene.
- 8. A method according to claim 7 wherein the temperature is up to about 25°
- C. and the phosgene flow rate is about 0.05-0.2 equivalent per equivalent of hydroxy compound per minute.
- 9. A method according to claim 7 wherein the temperature is 25°
- -30°
C. and the phosgene flow rate is about 0.05-0.25 equivalent per equivalent of hydroxy compound per minute.
- 10. A method according to claim 7 wherein the temperature is above 30°
- C. and the phosgene flow rate is about 0.2-0.4 equivalent per equivalent of hydroxy compound per minute.
Specification
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- Resources
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Current AssigneeCyclics Corporation
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Original AssigneeGeneral Electric Company
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InventorsShannon, Thomas G., Brunelle, Daniel J., Rosenquist, Niles R.
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Primary Examiner(s)Helfin, Bernard
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Application NumberUS06/790,909Time in Patent Office453 DaysField of Search260/463, 558/280, 558/281, 558/282US Class Current558/281CPC Class CodesC07C 68/02 from phosgene or haloformatesC07C 69/96 Esters of carbonic or halof...
