Method for producing, via organometallic compounds, organic intermediate products
View Patent ↗A method for preparing aryllithium compounds of the formulae (IV) and (VI) includes reacting halogen compounds (I) with lithium metal to obtain a lithium compound of formula (II) and reacting the lithium compound of formula (II) with aromatic compounds of the formulae (III) and/or (V) to form lithium aromatics (IV) and (VI).
1. A process for preparing aryllithium compounds of the formulae (IV) and (VI) comprising the steps of
a. reacting at least one halogen compound (I) with lithium metal to form a lithium compound of the formula (II)
b. reacting the lithium compound of formula (II) with aromatic compounds of the formulae (III) and/or (V) to deprotonate the aromatic compounds of formulae (III) and/or (V) and form lithium aromatics of formulae (IV) and/or (VI), wherein the steps a) and b) are carried out as a one-pot reaction,
where R is methyl, a primary, secondary or tertiary alkyl radical having from 2 to 12 carbon atoms, alkyl substituted by a radical selected from the group consisting of phenyl, substituted phenyl, aryl, heteroaryl, alkoxy, dialkylamino, alkylthio and substituted or unsubstituted cycloalkyl having from 3 to 8 carbon atoms,
Hal=fluorine, chlorine, bromine or iodine,
X 1-4 are, independently of one another, each carbon or two adjacent radicals X 1-4 R 1-4 can together be O, or S;
the radicals R 1-4 and the radical Z are substituents selected from the group consisting of hydrogen, methyl, primary, secondary or tertiary, cyclic or acyclic alkyl radicals having from 2 to 12 carbon atoms, substituted cyclic or acyclic alkyl groups, alkoxy, dialkylamino, alkylamino, arylamino, diarylamino, phenyl, substituted phenyl, alkylthio, diarylphosphino, dialkyiphosphino, dialkylaminocarbonyl or diarylaminocarbonyl, monoalkylaminocarbonyl or monoarylaminocarbonyl, CO 2 − , hydroxyalkyl, alkoxyalkyl, fluorine and chlorine, CN and heteroaryl or two adyacent radicals R 1-4 form an aromatic or aliphatic ring.
2. The process as claimed in claim 1 , wherein the process is carried out at temperatures in the range from −100 to +25° C.
3. The process as claimed in claim 1 , wherein the amount of lithium to be added per mole of halogen to be reacted is in the range from 1.95 to 2.5 mol.
4. The process as claimed claim 1 , wherein the process is carried out in an ether solvent.
5. The process as claimed in claim 1 , said process further comprising adding organic redox systems to the reaction of the Li metal in step a).
6. The process as claimed in claim 1 , wherein the compounds of the formula (III) or (V) include an alkoxy, F, Cl, substituted amino, CN, heteroaryl, aminoalkyl or hydroxyalkyl radical in the ortho position relative to the deprotonating hydrogen.
7. The process as claimed in claim 1 , further comprising the step of reacting the compounds of the formulae (IV) and/or (VI) with an electrophile.
8. The process as claimed in claim 7 , wherein the reaction with the electrophile is carried out either after production of the lithiated compound (IV) and/or (V) or in a one-pot process by simultaneous addition to the reaction mixture.
9. The process as claimed in claim 7 , wherein the electrophile is selected from the group consisting of carbon, boron or silicon compounds.
10. The process as claimed in claim 1 , wherein two adjacent radicals R 1-4 form an aromatic or aliphatic ring.
11. A process as claimed in claim 1 , wherein the lithium compound of the formula (II) is present in a concentration ranging from 5 to 30% by weight.
12. A process for preparing aryllithium compounds of the formula (IV) and (VI) comprising the steps of
a. reacting at least one halogen compound (I) with lithium metal to form a lithium compound of the formula (II)
b. reacting the lithium compound of formula (II) with aromatic compounds of the formula (III) and/or (V) to deprotonate the aromatic compounds of formula (III) and/or (V) and form lithium aromatics of formula (IV) and/or (VI).
where R is methyl, a primary, secondary or tertiary alkyl radical having from 2 to 12 carbon atoms, alkyl substituted by a radical selected from the group consisting of phenyl, substituted phenyl, aryl, heteroaryl, alkoxy, dialkylamino, alkylthio and substituted or unsubstituted cycloakyl having from 3 to 8 carbon atoms,
Hal=fluorine, chlorine, bromine or iodine,
X 1-4 are, independently of one another, each carbon or two adjacent radicals X 1-4 R 1-4 can together be O, or S;
the radicals R 1-4 and the radical Z are substituents selected from the group consisting of hydrogen, methyl, primary, secondary or tertiary, cyclic or acyclic alkyl radicals having from 2 to 12 carbon atoms, substituted cyclic or acyclic alkyl groups, alkoxy, dialkylamino, alkylamino, arylamino, diarylamino, phenyl, substituted phenyl, alkylthio, diarylphosphino, dialkylphosphino, dialkylaminocarbonyl or diarylaminocarbonyl, monoalkylaminocarbonyl or monoarylaminocarbonyl, CO 2 − , hydroxyalkyl, alkoxyalkyl, fluorine and chlorine, CN and heteroaryl, or two adjacent radicals R 1-4 form an aromatic or aliphatic ring,
wherein (I) the process is carried out at temperatures in the range from −100 to −25° C. and (II) the process is carried out in an ether solvent.