US4018819A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the manufacture of 2-chloroethane-phosphonic acid
Assignee: Hoechst AG
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Filing: 1975-08-19
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Granted: 1977-04-19
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Expires: 1995-08-19
Abstract
Abstract An improved process for the manufacture of 2-chloroethane phosphonic acid in which 2-chloroethane phosphonic acid bis(2-chloroethyl)-ester is heated with excess hydrogen chloride in the presence of 0.1 to 31% by weight of water at temperatures above 100° C under pressure, the 1,2-dichloroethane formed during the reaction is continuously or discontinuously distilled off and the decrease in pressure is compensated by adding gaseous hydrogen chloride.
Inventors
- 👤 Karl Rehn
- 👤 Otto Schaffner
- 👤 Gerhard Stahler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:16
CPC Classifications
C; C07; C07F; C07F9/00; C07F9/02; C07F9/28; C07F9/38; C07F9/3804; C07F9/3808
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
78 words
In a process for the manufacture of 2-chloroethane-phosphonic acid by the hydrolytic cleavage of 2-chloroethane-phosphonic acid-bis(2-chloroethyl) ester by contacting said ester with hydrogen chloride in the presence of 0.1 to 31 percent of water, by weight of said ester, at a temperature above 100° C. and under an elevated pressure and maintaining an elevated pressure during the reaction by adding gaseous hydrogen chloride, the improvement which comprises distilling off during the reaction the 1,2-dichloroethane formed by the reaction.
Claim 2
Dependent Claim
78 words
In a process for the manufacture of 2-chloroethane-phosphonic acid by the hydrolytic cleavage of 2-chloroethane-phosphonic acid-bis(2-chloroethyl) ester by contacting said ester with hydrogen chloride in the presence of 0.1 to 31 percent of water, by weight of said ester, at a temperature above 100° C. and under an elevated pressure and maintaining an elevated pressure during the reaction by adding gaseous hydrogen chloride, the improvement which comprises distilling off during the reaction the 1,2-dichloroethane formed by the reaction.
Claim 3
Dependent Claim
23 words
The process of claim 1, wherein hydrochloric acid having a concentration of from 30 to 38% by weight is used for the cleavage.
Claim 4
Dependent Claim
19 words
The process of claim 1, wherein a pressure of from 1 to 10 atmospheres gauge is maintained during hydrolysis.
Claim 5
Dependent Claim
14 words
The process of claim 3, wherein the pressure is 3 to 6 atmospheres gauge.
Claim 6
Dependent Claim
20 words
The process of claim 1, wherein the hydrolysis is carried out at a temperature of from 110° to 190° C.
Claim 7
Dependent Claim
12 words
The process as in claim 1, wherein 1,2-dichloroethane is distilled off discontinuously.
Claim 8
Dependent Claim
12 words
The process as in claim 1, wherein 1,2-dichloroethane is distilled off continuously.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-04-18 | 1980-10-18 | 1981-04-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-18 | 1984-10-18 | 1985-04-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-18 | 1988-10-18 | 1989-04-19 | $7700.00 | Window Closed / Lapsed |