US4891455A
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Process for preparing monohalogenated cyclobutarenes
Assignee: Dow Chemical Co
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Filing: 1988-06-17
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Granted: 1990-01-02
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Expires: 2008-06-17
Abstract
Abstract Monohalogenated cyclobutarenes are prepared by halogenating a cyclobutarene in the presence of an organic complexing agent, an acid scavenger, or water. Faster reaction rates highly selective to monohalogenated cyclobutarenes are obtained without conventional heavy metal or halogen catalysts.
Inventors
- 👤 Ming-Biann Liu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 21:08
CPC Classifications
C; C07; C07C; C07C17/00; C07C17/093; C07C17/10; C07C17/12
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
29 words
A method of preparing monohalogenated cyclobutarenes consisting essentially of halogenating a cyclobutarene with a halogenating agent in the presence of an organic complexing agent, an acid scavenger, or water.
Claim 2
Independent Claim
29 words
A method of preparing monohalogenated cyclobutarenes consisting essentially of halogenating a cyclobutarene with a halogenating agent in the presence of an organic complexing agent, an acid scavenger, or water.
Claim 3
Dependent Claim
17 words
The method of claim 1 wherein the halogenating agent is a brominating agent or a chlorinating agent.
Claim 4
Dependent Claim
13 words
The method of claim 2 wherein the halogenating agent is a brominating agent.
Claim 5
Dependent Claim
10 words
The method of claim 3 wherein the cyclobutarene is benzocyclobutene.
Claim 6
Dependent Claim
22 words
The method of claim 4 wherein the chlorinating agent is selected from the group consisting of molecular chlorine, N-chlorosuccinimide and t-butyl hypochlorite.
Claim 7
Dependent Claim
12 words
The method of claim 5 wherein the chlorinating agent is molecular chlorine.
Claim 8
Dependent Claim
15 words
The method of claim 1 wherein the cyclobutarene is diluted in an appropriate nonreacting diluent.
Claim 9
Dependent Claim
29 words
The method of claim 7 wherein the diluent is selected from the group consisting of methylene chloride, ethylene dichloride, chloroform, carbon tetrachloride, bromochloromethane, hexane, acetic acid, methanol, and water.
Claim 10
Dependent Claim
11 words
The method of claim 8 wherein the diluent is methylene chloride.
Claim 11
Dependent Claim
28 words
The method of claim 1 wherein the organic complexing agent has an electron donor capacity equal to or slightly greater than the electron donor capacity of the cyclobutarene.
Claim 12
Dependent Claim
81 words
The method of claim 10 wherein the organic complexing agent is selected from the group consisting of saturated aliphatic alcohols and diols having less than 10 carbon atoms; aliphatic polymeric diols having an average molecular weight ranging from about 100 to about 15,000; saturated aliphatic ethers having less than 10 carbon atoms; saturated cyclic ethers: saturated quaternary ammonium salts: saturated carboxylic acids and their anhydrides having less than 10 carbon atoms; dimethyl formamide; dimethyl sulfoxide: and mixtures of these complexing agents.
Claim 13
Dependent Claim
60 words
The method of claim 11 wherein the organic complexing agent is selected from the group consisting of saturated aliphatic alcohols and diols having less than 10 carbon atoms: aliphatic polymeric diols having an average molecular weight ranging from about 100 to about 15,000: saturated aliphatic ethers having less than 10 carbon atoms; saturated cyclic ethers; and saturated quaternary ammonium salts.
Claim 14
Dependent Claim
56 words
The method of claim 11 wherein the organic complexing agent is selected from the group consisting of saturated aliphatic alcohols and diols having less than 10 carbon atoms: aliphatic polymeric diols having an average molecular weight ranging from about 100 to about 15,000: saturated aliphatic ethers having less than 10 carbon atoms: and saturated cyclic ethers.
Claim 15
Dependent Claim
53 words
The method of claim 11 wherein the organic complexing agent is selected from the group consisting of saturated aliphatic alcohols and diols having less than 10 carbon atoms; aliphatic polymeric diols having an average molecular weight ranging from about 100 to about 15,000; and saturated aliphatic ethers having less than 10 carbon atoms.
Claim 16
Dependent Claim
38 words
The method of claim 11 wherein the organic complexing agent is selected from the group consisting of saturated aliphatic alcohols and diols having less than 10 carbon atoms, and saturated aliphatic ethers having less than 10 carbon atoms.
Claim 17
Dependent Claim
23 words
The method of claim 15 wherein the organic complexing agent is selected from the group consisting of methanol and ethylene glycol ethyl ether.
Claim 18
Dependent Claim
12 words
The method of claim 16 wherein the organic complexing agent is methanol.
Claim 19
Dependent Claim
26 words
The method of claim 6 wherein the mole ratio of the cyclobutarene to the organic complexing agent or water ranges from about 0.05:1 to about 4.0:1.
Claim 20
Dependent Claim
23 words
The method of claim 1 wherein the acid scavenger reacts readily with hydrogen halide but does not react readily with the halogenating agent.
Claim 21
Dependent Claim
11 words
The method of claim 6 wherein the acid scavenger is organic.
Claim 22
Dependent Claim
59 words
The method of claim 20 wherein the organic acid scavenger is selected from the group consisting of epoxides having less than 10 carbon atoms; aliphatic tertiary alcohols having less than 10 carbon atoms: alkali metal and alkali earth metal salts of aliphatic alcohols having less than 10 carbon atoms: aliphatic primary, secondary, and tertiary amines: heterocyclic compounds: and triarylphosphines.
Claim 23
Dependent Claim
27 words
The method of claim 21 wherein the organic acid scavenger is selected from the group consisting of epoxides having less than 10 carbon atoms and tertiary amines.
Claim 24
Dependent Claim
20 words
The method of claim 22 wherein the organic acid scavenger is selected from the group consisting of epichlorohydrin and triethylamine.
Claim 25
Dependent Claim
11 words
The method of claim 1 wherein the acid scavenger is inorganic.
Claim 26
Dependent Claim
47 words
The method of claim 24 wherein the inorganic acid scavenger is selected from the group consisting of alkali metal and alkali earth metal salts of alcohols and carboxylic acids, alkali metal and alkali earth metal bases, and carbonates and bicarbonates of alkali metal and alkali earth metals.
Claim 27
Dependent Claim
13 words
The method of claim 25 wherein the inorganic acid scavenger is sodium methylate.
Claim 28
Dependent Claim
23 words
The method of claim 1 wherein the mole ratio of the cyclobutarene to the acid scavenger ranges from about 0.5:1 to about 2.0:1.
Claim 29
Dependent Claim
21 words
The method of claim 1 wherein the weight ratio of diluent to the cyclobutarene ranges from about 0.5:1 to about 20:1.
Claim 30
Dependent Claim
23 words
The method of claim 1 wherein the mole ratio of the halogenating agent to the cyclobutarene ranges from about 0.90:1 to about 1.10:1.
Claim 31
Dependent Claim
25 words
The method of claim 1 wherein the selectivity of the reaction to monohalogenated cyclobutarenes ranges from about 75 mole percent to about 95 mole percent.
Claim 32
Dependent Claim
14 words
The method of claim 1 wherein the halogenation reaction is maintained at atmospheric pressure.
Claim 33
Dependent Claim
18 words
The method of claim 31 wherein the halogenating agent is added continuously or periodically during the bromination step.
Claim 34
Dependent Claim
21 words
The method of claim 32 wherein the temperature is maintained in the range of about 25° C. to about 60° C.
Claim 35
Dependent Claim
25 words
The method of claim 1 wherein the mole ratio of the cyclobutarene to the complexing agent or water ranges from about 0.05:1 to about 6.0:1.
References Cited (Backward Citations)
US4540011A
Cited
US4540763A
Cited
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