- Melphalan intermediate and preparation method thereof
-
The invention discloses a Melphalan intermediate and a preparation method thereof. The Melphalan intermediate is prepared by acidifying a compound p-nitrobenzaldehyde under the action of methanol, a hydrochloric acid solvent, etc. The preparation method has a route with mild reaction conditions, is higher than an existing preparation method in yield, is economical and effective, and is suitable for large-scale industrial production. The synthesis route is as shown in the description.
- -
-
Paragraph 0043; 0058; 0063-0064; 0107; 0122; 0127-0128; 0171
(2019/08/02)
-
- Asymmetric chemoenzymatic synthesis of N-acetyl-α-amino esters based on lipase-catalyzed kinetic resolutions through interesterification reactions
-
Several phenylalanine analogs have been synthesized through a four-step route starting from easily available ethyl acetamidocyanoacetate. In a first reaction, and making use of phase transfer catalysts, this compound reacted with several alkyl halides, being benzyltributylammonium chloride identified as the best one for the production of a series of quaternary amino acids in moderate to excellent yields (52-95%). Then, the corresponding N-acetyl-phenylalanine methyl and allyl ester derivatives were obtained through acidic hydrolysis, esterification, and N-acetylation. Rhizomucor miehei lipase was found as a versatile enzyme for the resolution of these amino esters, finding the best results through interesterification reactions with butyl butyrate in acetonitrile. A great influence in the stereoselectivity was found depending on the chemical structure of the compound, achieving for the non- or para-substituted in the phenyl ring excellent stereoselectivities, being moderate for the meta-nitro derivative, while the ortho-nitro amino ester did not react.
- Da Silva, Marcos Reinaldo,De Mattos, Marcos Carlos,De Oliveira, Maria Da Concei??o Ferreira,De Lemos, Telma Leda Gomes,Ricardo, Nágila Maria Pontes Silva,De Gonzalo, Gonzalo,Lavandera, Iván,Gotor-Fernández, Vicente,Gotor, Vicente
-
p. 2264 - 2271
(2014/03/21)
-
- Anthranilic acid based CCK1 receptor antagonists: Preliminary investigation on their second "touch point"
-
In this phase of structure-affinity relationship study of VL-0395, a new anthranilic acid based CCK1 selective antagonist, we propose a series of unnatural aminoacidic derivatives. The result of this work is the identification of a new CCK ligand, which possesses an affinity (IC50 = 35 nm) one order of magnitude greater than the lead and, as a general rule, it points out how the hypothesized receptorial pocket which accommodates the Phe residue allows much more structural modification than that interacting with the N-terminal group. Hence, the modification of the C-terminal pharmacophoric group of our lead VL-0395 can not only enhance the affinity of anthranilic acid derivatives but can modulate the selectivity for one CCK receptor subtype or afford mixed antagonists.
- Varnavas, Antonio,Lassiani, Lucia,Valenta, Valentina,Mennuni, Laura,Makovec, Francesco,Hadjipavlou-Litina, Dimitra
-
p. 563 - 581
(2007/10/03)
-
- UNUSUAL AMINO ACIDS. III. ASYMMETRIC SYNTHESIS OF 3-ARYLALANINES
-
21 (Z)-α-N-benzoylamino-β-arylacrylic acids and their esters were prepared by known procedures and hydrogenated to the corresponding optically active α-benzoyl-β-arylalanine derivatives with optical yields in the range of 82-95percent ee using the cationi
- Taudien, Stefan,Schinkowski, Klaus,Krause, Hans-Walter
-
-