US4189610A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of 4,4-dioxy-substituted stilbenes
Assignee: Monsanto Co
•
Filing: 1977-10-31
•
Granted: 1980-02-19
•
Expires: 1997-10-31
Abstract
Abstract Dehydrohalogenation-rearrangement of 1,1-bis(4-oxy-substituted aryl)-2-haloethanes to yield 4,4'-dioxysubstituted stilbenes is effected by heating an acidic reaction medium comprising the 1,1-bis(4-oxy-substituted aryl)-2-haloethane dissolved in a solution of an aliphatic carboxylic acid and a carboxylic acid salt. The process is particularly directed to the preparation of 4,4'-dihydroxystilbene from 1,1-bis(4-hydroxyphenyl)-2-chloroethane.
Inventors
- 👤 James P. Coleman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 10:05
CPC Classifications
C; C07; C07C; C07C41/00; C07C41/01; C07C41/18; C07C41/24; C07C37/00; C07C37/11; C07C37/115; C07C41/30; Y; Y02; Y02P; Y02P20/00; Y02P20/50; Y02P20/582
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
136 words
A process for the preparation of 4,4'-dioxy-substituted stilbenes which comprises heating an acidic reaction medium comprising a 1,1-bis(4-oxy-substituted aryl)-2-haloethane dissolved in a solution of an aliphatic carboxylic acid and a soluble acid salt to a temperature between about 100° C. and about 250° C., and for a time, sufficient to cause dehydrohalo-genation-rearrangement of the 1,1-bis(4-oxy-substituted aryl)-2-haloethane to yield the 4,4'-dioxy-substituted stilbene, with the aforesaid 1,1-bis(4-oxy-substituted aryl)-2-haloethanes being represented by the formula: ##STR4## in which X independently represents a halogen selected from the group consisting of chlorine, bromine, and iodine; Y independently represents a non-interfering hydrocarbyl group; Z represents hydrogen or Y; and m and n each independently represent an integer from zero (0) to 4, inclusive, with the proviso that the sum of m and n, with respect to each aryl ring, does not exceed 4.
Claim 2
Dependent Claim
136 words
A process for the preparation of 4,4'-dioxy-substituted stilbenes which comprises heating an acidic reaction medium comprising a 1,1-bis(4-oxy-substituted aryl)-2-haloethane dissolved in a solution of an aliphatic carboxylic acid and a soluble acid salt to a temperature between about 100° C. and about 250° C., and for a time, sufficient to cause dehydrohalo-genation-rearrangement of the 1,1-bis(4-oxy-substituted aryl)-2-haloethane to yield the 4,4'-dioxy-substituted stilbene, with the aforesaid 1,1-bis(4-oxy-substituted aryl)-2-haloethanes being represented by the formula: ##STR4## in which X independently represents a halogen selected from the group consisting of chlorine, bromine, and iodine; Y independently represents a non-interfering hydrocarbyl group; Z represents hydrogen or Y; and m and n each independently represent an integer from zero (0) to 4, inclusive, with the proviso that the sum of m and n, with respect to each aryl ring, does not exceed 4.
Claim 3
Dependent Claim
20 words
The process of claim 1 wherein the 1,1-bis(4-oxy-substituted aryl)-2-haloethane is a 1,1-bis(4-hydroxyaryl)-2-haloethane and the 4,4'-dioxy-substituted stilbene product is a 4,4'-dihydroxystilbene.
Claim 4
Dependent Claim
15 words
The process of claim 2 wherein the 1,1-bis(4-hydroxyaryl)-2-haloethane is 1,1-bis(4-hydroxyphenyl)-2-chloroethane and the 4,4'-dihydroxystilbene is 4,4'-dihydroxystilbene.
Claim 5
Dependent Claim
15 words
The process of claim 2 wherein the 1,1-bis(4-hydroxyaryl)-2-haloethane is 1,1-bis(3,5-di-t-butyl-4-hydroxyphenyl)-2-chloroethane and the 4,4'-dihydroxystilbene is 3,5,3',5'-tetra-t-butyl-4,4'-dihydroxystilbene.
Claim 6
Dependent Claim
19 words
The process of claim 1 wherein the 1,1-bis(4-oxy-substituted aryl)-2-haloethane is a 1,1-bis(4-alkoxyaryl)-2-haloethane and the 4,4'-dioxy-substituted stilbene is a 4,4'-dialkoxystilbene.
Claim 7
Dependent Claim
24 words
The process of claim 5 wherein the 1,1-bis(4-alkoxyaryl)-2-haloethane is 1,1-bis(4-methoxyphenyl)-2-chloroethane selected from the group consisting of 1,1-bis(4-methoxyphenyl)-2-bromoethane and 1,1-bis(4-methoxyphenyl)-2-iodoethane, and the 4,4'-dialkoxystilbene is 4,4'-dimethoxystilbene.
Claim 8
Dependent Claim
13 words
The process of claim 1 wherein the aliphatic carboxylic acid is substantially anhydrous.
Claim 9
Dependent Claim
19 words
The process of claim 7 wherein the aliphatic carboxylic acid comprises C 2 to C 6 aliphatic carboxylic acids.
Claim 10
Dependent Claim
18 words
The process of claim 8 wherein the C 2 to C 6 aliphatic carboxylic acid is acetic acid.
Claim 11
Dependent Claim
12 words
The process of claim 1 wherein the carboxylic acid salt is pre-formed.
Claim 12
Dependent Claim
18 words
The process of claim 10 wherein the pre-formed carboxylic acid salt is an alkali metal carboxylic acid salt.
Claim 13
Dependent Claim
15 words
The process of claim 11 wherein the alkali metal carboxylic acid salt is sodium acetate.
Claim 14
Dependent Claim
24 words
The process of claim 1 wherein the carboxylic acid salt is formed in situ from the aliphatic carboxylic acid and added hydroxide ion-containing compound.
Claim 15
Dependent Claim
28 words
The process of claim 13 wherein the added hydroxide ion-containing compound is an alkali metal hydroxide and the carboxylic acid salt is an alkali metal carboxylic acid salt.
Claim 16
Dependent Claim
30 words
The process of claim 14 wherein the alkali metal hydroxide is sodium hydroxide, the aliphatic carboxylic acid is acetic acid, and the alkali metal carboxylic acid salt is sodium acetate.
Claim 17
Dependent Claim
18 words
The process of claim 1 wherein the dehydrohalogenation-rearrangement of the 1,1-bis(4-oxy-substituted aryl)-2-haloethane is conducted under an inert atmosphere.
Claim 18
Dependent Claim
11 words
The process of claim 16 wherein the inert atmosphere is nitrogen.
Claim 19
Dependent Claim
18 words
The process of claim 1 wherein the dehydrohalogenation-rearrangement of the 1,1-bis(4-oxy-substituted aryl)-2-haloethane is conducted at super atmospheric pressures.
Claim 20
Dependent Claim
19 words
The process of claim 18 wherein the super atmospheric pressures range between about 75 psig to about 150 psig.
Claim 21
Dependent Claim
25 words
The process of claim 1 wherein the time sufficient to cause dehydrohalogenation-rearrangement of the 1,1-bis(4-oxy-substituted aryl)-2-haloethane is between about 0.5 hours and about 5 hours.
Claim 22
Dependent Claim
44 words
The process of claim 1 wherein the concentration of the 1,1-bis(4-oxy-substituted aryl)-2-haloethane in the acidic reaction medium is between about 0.2 molar and about 2.0 molar and the gram-equivalent weight ratio of metal carboxylic acid salt to be 1,1-bis(4-oxy-substituted aryl)-2-haloethane is at least 1:1.
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) | 1983-02-18 | 1983-08-20 | 1984-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-02-18 | 1987-08-20 | 1988-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-02-18 | 1991-08-20 | 1992-02-19 | $7700.00 | Window Closed / Lapsed |