US2008171891A1PendingUtilityA1
Process for preparing carbamic ester derivatives
Est. expiryDec 10, 2024(expired)· nominal 20-yr term from priority
C07D 265/26C07C 271/28C07C 269/06C07C 269/02
57
PatentIndex Score
0
Cited by
0
References
0
Claims
Abstract
An improved process for preparing carbamic ester derivatives of the general formula (1) by reaction with carbon monoxide and water in the presence of a palladium catalyst is provided.
Claims
exact text as granted — not AI-modified1 . A process for preparing carbamic ester derivatives of the general formula (1)
in which
R 1 , R 2 , R 3 , R 4 are identical or different and are hydrogen, an alkyl, alkoxy, carboxyl, chlorine, fluorine radical or a phenyl radical which is optionally substituted by alkyl or alkoxy radicals, and
R is an alkyl, aryl or heteroaryl radical
comprising reacting compounds of the general formula (2)
where
X is bromine or iodine, and
R 1 , R 2 , R 3 , R 4 and R have the meanings stated for the general formula (1), with carbon monoxide and water in the presence of a palladium catalyst.
2 . The process according to claim 1 , wherein compounds of the general formula (2′)
in which
X is chlorine or bromine, and
R is a straight-chain or branched alkyl radical having 16-22 carbon atoms,
are reacted with carbon monoxide and water in the presence of a palladium catalyst to form a carbamic ester derivative of the general formula (1′)
where R has the meaning stated for the general formula (2′).
3 . The process according to claim 1 , wherein the palladium catalysts employed are of the type X 2 Pd(PPh 3 ) 2 , where Ph is an optionally substituted phenyl radical, and X is halogen, preferably chlorine or bromine.
4 . The process according to claim 3 , wherein X is chlorine or bromine.
5 . The process according to claim 1 , wherein the process is carried out in the presence of a base, preferably in the presence of primary, secondary or tertiary amines, acetates, carbonates or bicarbonates.
6 . The process according to claim 5 , wherein the process is carried out in the presence of primary, secondary or tertiary amines, acetates, carbonates or bicarbonates.
7 . The process according to claim 1 , wherein the preparation of the compounds of the general formula (2)
takes place by an optionally substituted aniline of the general formula (6)
either
Ia) being reacted with phosgene or a substance which generates phosgene in situ or comprises phosgene, and
Ib) the compound of the general formula (7) obtained in this way
being reacted with an alcohol of the formula ROH or
II) being reacted with a compound of the formula Cl—C(═O)OR and the compound of the general formula (8) obtained both by step (Ia) and (Ib), and the alternative step (II),
being subjected to a halogenation to form a compound of the general formula (2), where the radicals R 1 , R 2 , R 3 , R 4 and R in all the abovementioned formulae have the meanings stated for the general formula (1).
8 . The process according to claim 1 , wherein the preparation of the compounds of the general formula (2) takes place by an optionally substituted aniline of the general formula (6)
1) being subjected to a halogenation and
2) the compound of the general formula (9) obtained in this way
either
IIIa) being reacted with phosgene or a substance which generates phosgene in situ or comprises phosgene, and
IIIb) the compound of the formula (10) obtained in this way
being reacted with an alcohol of the formula ROH or
IV) being reacted in a single step with Cl—C(═O)OR,
where the radicals R 1 , R 2 , R 3 , R 4 and R in all the abovementioned formulae have the meanings stated for the general formula (1).
9 . A process for preparing 2-alkyloxy-6-methyl-4H-3,1-benzoxazin-4-ones of the general formula (11)
comprising reacting compounds of the general formula (2)
with carbon monoxide and water in the presence of a palladium catalyst to form carbamic ester derivatives of the general formula (1)
and reacting such carbamic ester derivatives of the general formula (1) with methyl or ethyl chloroformate,
where R 1 , R 2 , R 3 , R 4 and R in all the abovementioned formulae always have the meanings stated for the general formula (1).
10 . The process according to claim 9 , wherein the preparation of the compounds of the general formula (2)
takes place by an optionally substituted aniline of the general formula (6)
either
Ia) being reacted with phosgene, and
Ib) the compound of the general formula (7) obtained in this way
being reacted with an alcohol of the formula ROH or
II) being reacted with a compound of the formula Cl—C(═O)OR and the compound of the general formula (8) obtained both by step (Ia) and (Ib), and the alternative step (II),
being subjected to a halogenation to form a compound of the general formula (2), where the radicals R 1 , R 2 , R 3 , R 4 and R in all the abovementioned formulae have the meanings stated for the general formula (1).
11 . The process according to claim 9 , wherein the preparation of the compounds of the general formula (2) takes place by an optionally substituted aniline of the general formula (6)
1) being subjected to a halogenation and
2) the compound of the general formula (9) obtained in this way
either
IIIa) being reacted with trichloromethyl chloroformate (diphosgene), and
IIIb) the compound of the formula (10) obtained in this way
being reacted with an alcohol of the formula ROH or
IV) being reacted in a single step with Cl—C(═O)OR,
where the radicals R 1 , R 2 , R 3 , R 4 and R in all the abovementioned formulae have the meanings stated for the general formula (1).Join the waitlist — get patent alerts
Track US2008171891A1 — get alerts on status changes and closely related new filings.
We store only your email — no account needed. See our privacy policy.