US4471137A
Expired / Lapsed
US
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Highly sterically hindered guanidines and process for the production thereof
Assignee: Centre National de la Recherche Scientifique
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Filing: 1982-07-14
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Granted: 1984-09-11
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Expires: 2002-07-14
Abstract
Abstract Compounds of the formula ##STR1## in which R 1 , R 1 ', R 2 , R 2 ' and R 3 independently represent a C 1-6 alkyl radical, in addition to which R 3 may represent a hydrogen atom, the alkyl radicals together containing in all at least 8 carbon atoms, are provided for use as highly sterically hindered bases in chemical syntheses.
Inventors
- 👤 Derek H. R. Barton
- 👤 John D. Elliott
- 👤 Stephan D. Gero
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 14:49
CPC Classifications
C; C07; C07C; C07C279/00; C07C279/04
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
102 words
A highly sterically hindered guanidine of formula I ##STR11## in which: R 1 , R 1 ', R 2 , R 2 ' and R 3 independently represent a hydrogen atom, a methyl, ethyl, isopropyl or tertiary butyl radical, R 1 , R' 1 , R 2 , R' 2 and R 3 together containing in all at least 8 carbon atoms, with the proviso that when the four radicals R 1 , R 1 ', R 2 , R 2 ', all represent a methyl radical or all represent an ethyl radical, then R 3 is not a tertiary butyl radical.
Claim 2
Dependent Claim
102 words
A highly sterically hindered guanidine of formula I ##STR11## in which: R 1 , R 1 ', R 2 , R 2 ' and R 3 independently represent a hydrogen atom, a methyl, ethyl, isopropyl or tertiary butyl radical, R 1 , R' 1 , R 2 , R' 2 and R 3 together containing in all at least 8 carbon atoms, with the proviso that when the four radicals R 1 , R 1 ', R 2 , R 2 ', all represent a methyl radical or all represent an ethyl radical, then R 3 is not a tertiary butyl radical.
Claim 3
Dependent Claim
16 words
A high sterically hindered guanidine according to claim 1, which is: N-t-butyl-N',N'-diethyl-N",N"-diisopropylguanidine, N-ethyl-N',N',N",N"-tetraisopropylguanidine, N,N,N',N'-tetraisopropylguanidine, or N-t-butyl-N',N',N",N"-tetraisopropylguanidine.
Claim 4
Dependent Claim
31 words
A process according to claim 1, in which the guanidine of formula: ##STR12## is prepared by reacting t-butylamine with an appropriate compound corresponding to formula III in the presence of n-butyllithium.
Claim 5
Dependent Claim
135 words
A process for the preparation of a guanidine according to claim 1, said process selected from (a) the process, in which R 1 , R' 1 , R 2 and R' 2 are all C 3-6 alkyl radicals, by the action of phosgene on a thiourea of formula IV: ##STR13## in a solvent to obtain a Vilsmeier salt of formula III: ##STR14## and reacting an amine of formula II: R.sub.3 NH.sub.2 (II) with said Vilsmeier salt, and (b) the process in which R 1 , R' 1 , R 2 and R' 2 are all methyl or ethyl, by the action of phosgene on a urea of formula V: ##STR15## in a solvent to obtain a Vilsmeier salt of formula III, and reacting the amine of formula II: R.sub.3 NH.sub.2 (II) with said Vilsmeier salt.
Claim 6
Dependent Claim
77 words
In a process of chemical synthesis using a highly sterically hindered base the improvement comprising the use of a guanidine of formula: ##STR16## in which R 1 , R' 1 , R 2 , R' 2 and R 3 independently represent a C 1 -C 6 alkyl radical, in addition to which R 3 may represent a hydrogen atom, the alkyl radicals together containing in all at least 8 carbon atoms, as a highly sterically hindered base.
Claim 7
Dependent Claim
77 words
In a process of chemical synthesis using a highly sterically hindered base the improvement comprising the use of a guanidine of formula: ##STR16## in which R 1 , R' 1 , R 2 , R' 2 and R 3 independently represent a C 1 -C 6 alkyl radical, in addition to which R 3 may represent a hydrogen atom, the alkyl radicals together containing in all at least 8 carbon atoms, as a highly sterically hindered base.
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) | 1987-09-11 | 1988-03-12 | 1988-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-09-11 | 1992-03-12 | 1992-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-09-11 | 1996-03-12 | 1996-09-11 | $7700.00 | Window Closed / Lapsed |