US4018838A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of preparing alkenes
Assignee: Imperial Chemical Industries Ltd
•
Filing: 1976-04-09
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Granted: 1977-04-19
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Expires: 1996-04-09
Abstract
Abstract The invention relates to the reductive dehydrohalogenation of α -haloalcohols to alkenes with powdered zinc in glacial acetic acid.
Inventors
- 👤 Peter John Vernon Cleare
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 10:58
CPC Classifications
C; C07; C07C; C07C17/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
73 words
A process for the preparation of a compound of formula: ##STR10## wherein X is halogeno and R is either a group of formula: ##STR11## or a group of formula: ##STR12## which comprises treating a haloalcohol of formula: ##STR13## with powdered zinc in glacial acetic acid at a temperature within the range 25° to 110° C, wherein the zinc is used in an amount of from one to two moles per mole of haloalcohol.
Claim 2
Dependent Claim
73 words
A process for the preparation of a compound of formula: ##STR10## wherein X is halogeno and R is either a group of formula: ##STR11## or a group of formula: ##STR12## which comprises treating a haloalcohol of formula: ##STR13## with powdered zinc in glacial acetic acid at a temperature within the range 25° to 110° C, wherein the zinc is used in an amount of from one to two moles per mole of haloalcohol.
Claim 3
Dependent Claim
18 words
A process as claimed in claim 1 conducted at a temperature within the range 40° to 60° C.
Claim 4
Dependent Claim
28 words
A process as claimed in claim 1 in which the quantity of zinc used is within the range 1.4 to 1.6 moles of zinc per mole of haloalcohol.
Claim 5
Dependent Claim
111 words
A process for the preparation of a compound of formula: ##STR14## where X is chloro or bromo, which comprises a. the step of treating a haloalcohol of formula: ##STR15## wherein R represents either the group of formula: ##STR16## or the group of formula: ##STR17## with powdered zinc in glacial acetic acid at a temperature within the range 25° to 110° C, wherein the zinc is used in an amount of from one to two moles per mole of haloalcohol; and b. the additional step of subsequently heating the reaction mixture at a temperature within the range 80° to 120° with a catalytic quantity of an organic acid other than acetic acid.
Claim 6
Dependent Claim
111 words
A process for the preparation of a compound of formula: ##STR14## where X is chloro or bromo, which comprises a. the step of treating a haloalcohol of formula: ##STR15## wherein R represents either the group of formula: ##STR16## or the group of formula: ##STR17## with powdered zinc in glacial acetic acid at a temperature within the range 25° to 110° C, wherein the zinc is used in an amount of from one to two moles per mole of haloalcohol; and b. the additional step of subsequently heating the reaction mixture at a temperature within the range 80° to 120° with a catalytic quantity of an organic acid other than acetic acid.
Claim 7
Dependent Claim
23 words
A process as claimed in claim 4 wherein the reaction mixture is heated at the reflux temperature in the presence of p-toluenesulphonic acid.
Claim 8
Dependent Claim
30 words
A process as claimed in claim 1 in which the haloalcohol is the product obtained by the reaction of a trihaloacetaldehyde and isobutylene in the presence of a Friedel-Crafts catalyst.
Claim 9
Dependent Claim
31 words
A process as claimed in claim 4 in which the haloalcohol is the product obtained by the reaction of anhydrous chloral or bromal and isobutylene in the presence of aluminium chloride.
References Cited (Backward Citations)
JPS4211041Y1
Cited
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 |