US4012405A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of ethyl chlorothioformate
Assignee: Zeneca Inc
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Filing: 1975-11-28
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Granted: 1977-03-15
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Expires: 1995-11-28
Abstract
Abstract An improved process for producing ethyl chlorothioformate by the reaction of ethyl mercaptan with phosgene. The process is conducted in two stages, both occurring in a continuous liquid phase, in the presence of an activated carbon catalyst. Production of by-product diethyl disulfide is minimized and overall capacity can be increased.
Inventors
- 👤 Carlo G. Alesandrini, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 21:31
CPC Classifications
C; C07; C07C; C07C329/00; Y; Y02; Y02P; Y02P20/00; Y02P20/50; Y02P20/582
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
77 words
A process for production of ethyl chlorothioformate comprising: a. contacting ethyl mercaptan with phosgene in a first continuous liquid phase reaction zone in the presence of a catalyst comprising activated carbon; b. removing a first reaction product from the first reaction zone; c. contacting the first reaction product with a catalyst comprising activated carbon in a second continuous liquid phase reaction zone; and d. removing a second reaction product comprising ethyl chlorothioformate from the second reaction zone.
Claim 2
Dependent Claim
77 words
A process for production of ethyl chlorothioformate comprising: a. contacting ethyl mercaptan with phosgene in a first continuous liquid phase reaction zone in the presence of a catalyst comprising activated carbon; b. removing a first reaction product from the first reaction zone; c. contacting the first reaction product with a catalyst comprising activated carbon in a second continuous liquid phase reaction zone; and d. removing a second reaction product comprising ethyl chlorothioformate from the second reaction zone.
Claim 3
Dependent Claim
25 words
A process according to claim 1 in which step (c) is operated at an average outlet temperature of between about 0° and about 70° C.
Claim 4
Dependent Claim
25 words
A process according to claim 1 in which step (c) is operated at an average outlet temperature of between about 10° and about 50° C.
Claim 5
Dependent Claim
26 words
A process according to claim 1 in which step (c) is operated at an average outlet temperature of between about 10° and below about 50° C.
Claim 6
Dependent Claim
24 words
A process according to claim 1 in which step (c) is operated at a residence time of between about 5 and about 90 minutes.
Claim 7
Dependent Claim
24 words
A process according to claim 5 in which step (c) is operated at a residence time of between about 45 and about 90 minutes.
Claim 8
Dependent Claim
18 words
A process according to claim 1 in which an excess of liquid phosgene is introduced into step (a).
Claim 9
Dependent Claim
18 words
A process according to claim 1 in which an excess of liquid phosgene is introduced into step (c).
Claim 10
Dependent Claim
27 words
A process according to claim 1 further comprising recovering unreacted starting materials from the product of step (d) and recycling said unreacted starting materials to step (c).
Claim 11
Dependent Claim
27 words
A process according to claim 1 further comprising recovering unreacted starting materials from the product of step (d) and recycling said unreacted starting materials to step (a).
Claim 12
Dependent Claim
17 words
A process according to claim 1 further comprising recovering ethyl chlorothioformate from the products of step (d).
Claim 13
Dependent Claim
34 words
A process according to claim 1 in which step (c) is conducted by introducing the first reaction product into the lower portion of a packed bed reactor containing a bed of activated carbon catalyst.
Claim 14
Dependent Claim
49 words
In a process for the production of ethyl chlorothioformate by the reaction of ethyl mercaptan with phosgene in the presence of a catalyst comprising activated carbon in a system comprising two reactors operating in a series, the improvement comprising operating the second reactor as a continuous liquid phase reactor.
Claim 15
Dependent Claim
49 words
In a process for the production of ethyl chlorothioformate by the reaction of ethyl mercaptan with phosgene in the presence of a catalyst comprising activated carbon in a system comprising two reactors operating in a series, the improvement comprising operating the second reactor as a continuous liquid phase reactor.
Claim 16
Dependent Claim
20 words
A process according to claim 12 in which the second reactor is operated as a flooded upflow packed bed reactor.
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) | 1980-03-14 | 1980-09-13 | 1981-03-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-03-14 | 1984-09-13 | 1985-03-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-03-14 | 1988-09-13 | 1989-03-15 | $7700.00 | Window Closed / Lapsed |