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US5087764A
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Process for the preparation of 2,3-difluorobenzenes
Assignee: Merck Patent GmbH
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Filing: 1989-02-27
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Granted: 1992-02-11
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Expires: 2009-02-27
Abstract
Abstract 1,4-disubstituted 2,3-difluorobenzenes according to formula I are suitable as intermediates for the synthesis of liquid crystalline compounds.
Inventors
- 👤 Volker Reiffenrath
- 👤 Joachim Krause
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 15:18
CPC Classifications
C; C07; C07C; C07C25/00; C07C25/02; C07C25/13; C07D; C07D213/00; C07D213/02; C07D213/04; C07D213/24; C07D213/26; C07C17/00; C07C17/26; C07C17/263; C07C255/00; C07C255/49; C07C255/50; C07C255/53; C07C255/54; C07C39/00; C07C39/24; C07C39/26; C07C39/27; C07C39/42; C07C43/00; C07C43/02; C07C43/20; C07C43/225; C07C43/23; C07C45/00; C07C45/45; C07C45/46; C07C45/56; C07C45/562; C07C47/00; C07C47/52; C07C47/55; C07C47/575; C07C49/00; C07C49/76; C07C49/84; C07C63/00; C07C63/68; C07C63/70; C07C63/74; C07C65/00; C07C65/21; C09; C09K; C09K19/00; C09K19/04; C09K19/06; C09K19/08; C09K19/10; C09K19/12; C09K19/30; C09K19/3098; C07C2601/00; C07C2601/12; C07C2601/14; C07C2601/16; C09K2019/121; C09K2019/123
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
91 words
A process for the preparation of a 1-substituted 2,3-difluorophenol of the formula R.sup.3 --A.sup.0 --R.sup.1 wherein R 3 is OH; A 0 is 2,3-difluoro-1,4-phenylene; and R 1 is alkyl, perfluoroalkyl or alkenyl, in each case having 1-15 C atoms, wherein one or more non-adjacent CH 2 or CF 2 groups is optionally replaced by O; said process comprising: deprotonating in the 4-position a 1-substituted 2,3-difluorobenzene at a temperature below about -50° C. using an organometallic reagent; and reacting the resultant product with an electrophile, said electrophile being nitrobenzene,oxygen, or a peroxide.
Claim 2
Dependent Claim
91 words
A process for the preparation of a 1-substituted 2,3-difluorophenol of the formula R.sup.3 --A.sup.0 --R.sup.1 wherein R 3 is OH; A 0 is 2,3-difluoro-1,4-phenylene; and R 1 is alkyl, perfluoroalkyl or alkenyl, in each case having 1-15 C atoms, wherein one or more non-adjacent CH 2 or CF 2 groups is optionally replaced by O; said process comprising: deprotonating in the 4-position a 1-substituted 2,3-difluorobenzene at a temperature below about -50° C. using an organometallic reagent; and reacting the resultant product with an electrophile, said electrophile being nitrobenzene,oxygen, or a peroxide.
Claim 3
Dependent Claim
50 words
A 2,3-difluorophenol compound according to the formula R.sup.3 --A.sup.0 --R.sup.1 wherein R 3 is OH; A 0 is 2,3-difluoro-1,4-phenylene; and R 1 is alkyl, perfluoroalkyl or alkenyl, in each case having 1-15 C atoms, wherein one or more non-adjacent CH 2 or CF 2 groups is optionally repalced by O;
Claim 4
Dependent Claim
50 words
A 2,3-difluorophenol compound according to the formula R.sup.3 --A.sup.0 --R.sup.1 wherein R 3 is OH; A 0 is 2,3-difluoro-1,4-phenylene; and R 1 is alkyl, perfluoroalkyl or alkenyl, in each case having 1-15 C atoms, wherein one or more non-adjacent CH 2 or CF 2 groups is optionally repalced by O;
Claim 5
Dependent Claim
26 words
A process according to claim 1, wherein deprotonation occurs within a reaction solution and said electrophile is gaseous oxygen which is passed itno said reaction solution.
Claim 6
Dependent Claim
24 words
A process according to claim 1, wherein said organometallic reagent is an alkyl metal compound, an aryl metal compound, or an alkyl metal amide.
Claim 7
Dependent Claim
17 words
A process according to claim 1, wherein said organometallic reagent contains the metal Li, Na or K.
Claim 8
Dependent Claim
17 words
A process according to claim 4, wherein said organometallic reagent contains the metal Li, Na or K.
Claim 9
Dependent Claim
13 words
A process according to claim 1, wherein said organometallic reagent is n-butyl lithium.
Claim 10
Dependent Claim
13 words
A process according to claim 1, wherein said electrophile is lithium tert.-butyl peroxide.
Claim 11
Dependent Claim
14 words
A process according to claim 1, wherien said organometallic reagent contains Li or K.
Claim 12
Dependent Claim
12 words
A process according to claim 1, wherein said organometallic reagent contains Li.
Claim 13
Dependent Claim
15 words
A process according to claim 1, wherein said electrophile is H 2 O 2 .
Claim 14
Dependent Claim
35 words
A process according to claim 1, wherein said substituted 2,3-difluorophenol is: 4-methyl-2,3-difluorophenol, 4-ethyl -2,3-difluorophenol, 4-propyl-2,3-difluorophenol, 4-butyl-2,3-difluorophenol, 4-pentyl-2,3-difluorophenol 4-hexyl-2,3-difluorophenol, 4-octyl-2,3-difluorophenol, 4-nonyl -2,3-difluorophenol, 4-decyl-2,3-diflurophenol, 4-heptyl-2,3-difluorophenol, 4-methoxy-2,3-difluorophenol, 4-propoxy-2,3-difluorophenol, 4-butoxy -2,3-difluorophenol, 4-pentoxy-2,3-difluorophenol, 4-hexoxy-2,3-difluoorphenol, 4-heptoxy-2,3-difluorophenol, 4-octoxy-2,3-difluorophenol, 4-nonoxy-2,3-difluorophenol, or 4-decoxy -2,3-difluorophenol.
Claim 15
Dependent Claim
37 words
A compound according to claim 2, wherein said substituted 2,3-difluorophenol is: 4-methyl-2,3-difluorophenol, 4-ethyl -2,3-difluorophenol, 4-propyl-2,3-difluorophenol 4-butyl-2,3-difluorophenol, 4-pentyl-2,3-difluorophenol, 4-hexyl -2,3-difluorophenol, 4-octyl-2,3-difluorophenol, 4-nonyl-2,3-difluorophenol, 4-decyl -2,3-difluorophenol, 4-heptyl-2,3-difluorophenol, 4-methoxy-2,3-difluorophenol, 4-propoxy -2,3-difluorophenol, 4-butoxy-2,3difluorophenol, 4-pentoxy-2,3-difluorophenol, 4-hexoxy -2,3-difluorophenol, 4-heptoxy-2,3-difluorophenol, 4-octoxy-2,3-difluorophenol, 4-nonoxy -2,3-difluorophenol, or 4-decoxy-2,3-difluorophenol.
Claim 16
Dependent Claim
13 words
A process according to claim 1, wherein said substituted 2,3-difluorophenol is 4-ethoxy -2,3-difluorophenol.
Claim 17
Dependent Claim
13 words
A compound according to claim 2, wherein said substituted 2,3-difluorophenol is 4-ethoxy -2,3-difluorophenol.
References Cited (Backward Citations)
US4366330A
Cited
US4429153A
Cited
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