321-69-7Relevant articles and documents
Preparation method of flumazenil
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Paragraph 0076, (2021/06/22)
The invention discloses a preparation method of flumazenil, and belongs to the field of medicine synthesis. The method comprises the following steps: by taking 5-fluoro-2-nitrobenzoic acid as a raw material, carrying out condensation on 5-fluoro-2-nitrobenzoic acid and sarcosine ester, and then carrying out ring closing while reducing, so as to obtain 7-fluoro-3, 4-dihydro-4-methyl-1H-[1, 4] benzodiazepine-2, 5-diketone; and finally, carrying out halogenation and cycloaddition reaction to obtain flumazenil. According to the novel synthesis method of the flumazenil key intermediate 7-fluoro-3, 4-dihydro-4-methyl-1H-[1, 4] benzodiazepine-2, 5-diketone, provided by the invention, a green synthesis process is adopted, an intramolecular cyclization reaction is performed while a nitro group is reduced, and compared with a known flumazenil synthesis method, a strong oxidant, a highly toxic reagent (such as ethyl chloroformate) and the like are not needed, and the yield is higher.
Synthesis of Ring-Fused, N-Substituted 4-Quinolinones Using p Ka-Guided, Base-Promoted Annulations with Isatoic Anhydrides: Total Synthesis of Penicinotam
Khalifa, Muhammad M.,Philkhana, Satish Chandra,Golden, Jennifer E.
, p. 464 - 481 (2019/12/24)
An anionic annulation strategy employing isatoic anhydrides and a wide assortment of enolizable partners was developed to afford over 80 novel ring-fused, N-substituted 4-quinolinones, an underrepresented privileged template. Multiple factors governing the efficiency of the transformation were determined, resulting in a reliable and tunable synthetic platform applicable for a broad range of substrates with variable deprotonation susceptibility, such as tetramic and tetronic acids, cyclic 1,3-diketones, and cycloalkanones. Application to the synthesis of bioactive, pyrrolizine-fused 4-quinolinone, penicinotam 3, resulted in the most brief and highest yielding total synthesis of the alkaloid in three steps and a 36% overall yield.
Carbene-Catalyzed Enantioselective Decarboxylative Annulations to Access Dihydrobenzoxazinones and Quinolones
Lee, Ansoo,Zhu, Joshua L.,Feoktistova, Taisiia,Brueckner, Alexander C.,Cheong, Paul H.-Y.,Scheidt, Karl A.
supporting information, p. 5941 - 5945 (2019/04/03)
A direct decarboxylative strategy for the generation of aza-o-quinone methides (aza-o-QMs) by N-heterocyclic carbene (NHC) catalysis has been discovered and explored. This process requires no stoichiometric additives in contrast with current approaches. Aza-o-QMs react with trifluoromethyl ketones through a formal [4+2] manifold to access highly enantioenriched dihydrobenzoxazin-4-one products, which can be converted to dihydroquinolones through an interesting stereoretentive aza-Petasis–Ferrier rearrangement sequence. Complementary dispersion-corrected density functional theory (DFT) studies provided an accurate prediction of the reaction enantioselectivity and lend further insight to the origins of stereocontrol. Additionally, a computed potential energy surface around the major transition structure suggests a concerted asynchronous mechanism for the formal annulation.
