EP0442754B1
Expired / Lapsed
EP
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Reagents and methods for stereospecific fluoromethylation
Assignee: Prototek Inc
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Filing: 1991-02-15
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Granted: 1995-12-27
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Expires: 2011-02-15
Abstract
Abstract The preparation of magnesium benzyl fluoromalonate and other equivalent materials, the synthetic equivalents of the -CH2F moiety, is described. Reaction between these reagents and the in situ-formed imidazolides of various carboxylic acids gives beta-keto-alpha-fluoroesters, which upon hydrogenation and spontaneous decarboxylation yields fluoromethyl ketones in excellent yields. The overall transformation from RCOOH to RCOCH2F is thus illustrated.
Inventors
- 👤 James T. Palmer
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 18:48
CPC Classifications
C; C07; C07D; C07D207/00; C07D207/02; C07D207/04; C07D207/08; C07C; C07C271/00; C07C271/06; C07C271/08; C07C271/10; C07C271/18; C07C271/20; C07C271/22; C07C279/00; C07C279/04; C07C279/14; C07C303/00; C07C303/26; C07C327/00; C07C327/20; C07C327/22; C07C45/00; C07C45/61; C07C45/67; C07C45/673; C07C45/676; C07C67/00; C07C67/30; C07C67/333; C07C67/343; C07C69/00; C07C69/62; C07C69/63; C07D207/18; C07D207/22; C07D207/24; C07D207/26; C07D207/273
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
19 words
A magnesium fluoromalonate of the formula: wherein X is -0- or -S-, and R′ is a hydrogenolytically cleavable group.
Claim 2
Dependent Claim
15 words
The magnesium fluoromalonate of claim 1 wherein R′ is an aralkyl, polyhaloalkyl or alkylsilyl group.
Claim 3
Dependent Claim
12 words
The magnesium fluoromalonate of claim 2 wherein R′ is an aralkyl group.
Claim 4
Dependent Claim
15 words
The magnesium fluoromalonate of claim 3 wherein R′ is selected from benzyl arid substituted benzyl.
Claim 5
Dependent Claim
14 words
The magnesium fluoromalonate of any one of the preceding claims wherein X is -0-.
Claim 6
Dependent Claim
9 words
The magnesium fluoromalonate of claim 1 having the formula:
Claim 7
Dependent Claim
9 words
The magnesium fluoromalonate of claim 1 having the formula:
Claim 8
Independent Claim
42 words
A method for forming a beta-keto-alpha-fluoroester of a carboxylic acid which comprises the steps of a. converting the carboxylic acid to give the corresponding imidazolide, and b. reacting the imidazolide with a magnesium fluoromalonate according to any one of the preceding claims.
Claim 9
Dependent Claim
57 words
A method for forming a fluoromethyl ketone from a carboxylic acid which comprises the steps of a. and b. carrying out steps a and b as claimed in claim 8 to form a beta-keto-alpha-fluoroester of the carboxylic acid; and c. hydrogenating the beta-keto-alpha-fluoroester of the carboxylic acid thereby causing its decarboxylation and formation of the fluoromethyl ketone.
Claim 10
Independent Claim
77 words
A method for stereoselectively forming a fluoromethyl ketone from an amino acid which comprises the steps of a. converting the carboxyl group of the amino acid to give the corresponding imidazolide, b. reacting the imidazolide with a magnesium fluoromalonate according to any one of claims 1 to 7 to yield the corresponding beta-keto-alpha-fluoroester of the amino acid, and c. hydrogenating the beta-keto-alpha-fluoroester of the amino acid thereby causing its stereospecific decarboxylation and formation of the fluoromethyl ketone.
Claim 11
Dependent Claim
24 words
The method of claim 9 or 10 wherein in step c. the hydrogenation is carried out using hydrogen gas and a noble metal catalyst.
Claim 12
Dependent Claim
22 words
The method of claim 10 or claim 11 when appendant to claim 10 wherein the amino acid is an amino-blocked amino acid.
References Cited (Backward Citations)
No citation records indexed.
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