- α-Functionalization of Cyclic Secondary Amines: Lewis Acid Promoted Addition of Organometallics to Transient Imines
-
Cyclic imines, generated in situ from their corresponding N-lithiated amines and a ketone hydride acceptor, undergo reactions with a range of organometallic nucleophiles to generate α-functionalized amines in a single operation. Activation of the transient imines by Lewis acids that are compatible with the presence of lithium alkoxides was found to be crucial to accommodate a broad range of nucleophiles including lithium acetylides, Grignard reagents, and aryllithiums with attenuated reactivities.
- Paul, Anirudra,Seidel, Daniel
-
p. 8778 - 8782
(2019/06/07)
-
- Process for preparing 1-methyl-3-phenylpiperazine using a novel intermediate
-
The present invention describes an industrially advantageous process to prepare highly pure 1-Methyl-3-phenylpiperazine of Formula I that makes use of a novel piperazine derivative, 4-Benzyl-1-methyl-2-oxo-3-phenylpiperazine, represented by Formula II 1-Methyl-3-phenylpiperazine is a useful intermediate in the preparation of antidepressant Mirtazapine.
- -
-
-
- INTERMEDIATE COMPOUNDS FOR THE PREPARATION OF MIRTAZAPINE AND THE PRODUCTION METHODS THEREOF
-
Intermediate compounds for the preparation of mirtazapine and obtention methods thereof. A method is described for obtaining (±)-3-phenyl-1-methylpiperazine, an important intermediate for obtaining mirtazapine, which is based on imposing a cyclation reaction, in the presence of a reducing agent, on new compounds of general formula (I) in which Z is a leaving group capable of undergoing a nucleophylic displacement. A method is also described for obtaining the new compounds of formula (I).
- -
-
-
- Synthesis of piperazine ring
-
A novel process for preparing a compound of the formula I: whereinR1 denotes substituted or unsubstituted alkyl, alkoxy, aryl, aryloxy or arylalkoxy; R2 denotes substituted or unsubstituted alkyl, alkoxy, aryl, aryloxy, arylalkoxy, tosyl, formyl, acetyl or amine; and R3 denotes substituted or unsubstituted alkyl, alkoxy, aryl, aryloxy or arylalkoxy is disclosed. These compounds are useful in the synthesis of the antidepressant mirtazapine and other tetracyclic compounds.
- -
-
Page column 7
(2008/06/13)
-
- Novel method for the preparation of piperazine and its derivatives
-
A novel method for the synthesis of piperazine and its derivatives of formula 1, 1wherein R is selected from hydrogen, or a lower alkyl group having 1 to 6 carbon atoms or a phenylalkyl group the alkyl of which has 1 to 4 carbon atoms; R1 is selected from hydrogen, a methyl group, a phenyl group optionally substituted with an alkyl group having 1 to 6 carbon atoms, or a phenylalkyl group the alkyl of which has 1 to 4 carbon atoms; and R2 is selected from hydrogen, or a methyl group, or a fluoromethyl group; 2comprising the steps: a. reacting an ester of formula 11 with substituted or unsubstituted ethylenediamine of formula 7 to give 3,4-dehydropiperazine-2-one and its derivatives of formula 12, wherein R, R1, R2 are as defined above and R6 is a C1 to C4 linear or branched alkyl group; and b. reacting the 3,4-dehydro-piperazine-2-one and its derivatives of formula 12 with a reducing agent to yield the piperazine and its derivatives of formula 1.
- -
-
-
- Process for preparing piperazine derivatives
-
A process for preparing a piperazine derivative represented by the formula (V): comprising reacting 1-methyl-3-phenylpiperazine with 2-chloro-3-cyanopyridine in an aprotic polar organic solvent in the presence of a base and an alkali metal halide. The piperazine derivative and its oxalate are compounds useful as preparation intermediates of mirtazapine.
- -
-
-
