19409-26-8

Upstream product

• 18065-01-5 2-(2-nitrophenoxy)-1-phenyl-1-ethanone 
• 74413-04-0 3-phenyl-2H-1,4-benzoxazine-4-oxide 
• 2142-69-0 2-bromophenyl methyl ketone 
• 95-55-6 2-amino-phenol 
• 32503-27-8 tetra(n-butyl)ammonium hydrogensulfate 
• 70-11-1 α-bromoacetophenone 
• 532-27-4 1-chloroacetophenone 
• 62-53-3 aniline 
• 98-86-2 acetophenone 
• 88-75-5 2-hydroxynitrobenzene 
• 824-38-4 potassium 2-nitrophenoxide 
• 32683-55-9 2-(2-acetylamino-phenoxy)-1-phenyl-ethanone 

Downstream Products

• 61821-83-8 3,3'-diphenyl-2H,2'H-[2,2']bi[benzo[1,4]oxazinyl] 
• 61821-73-6 meso-3,3'-diphenyl-2H,2'H-2,2'-oxy-bis-benzo[1,4]oxazine 
• 70310-30-4 3,4-dihydro-3-phenyl-2H-1,4-benzoxazine 
• 1221687-20-2 (R)-7-chloro-2-phenyl-1,2,3,4-tetrahydroquinoxaline 
• 1441005-92-0 (R)-tert-butyl 3-phenyl-3,4-dihydro-2H-1,4-benzoxazine-4-carboxylate 

Relevant academic research and scientific papers

Kinetic Resolution by Lithiation: Highly Enantioselective Synthesis of Substituted Dihydrobenzoxazines and Tetrahydroquinoxalines

Kinetic resolution provided a highly enantioselective method to access a range of 3-aryl-3,4-dihydro-2H-1,4-benzoxazines using n-butyllithium and the chiral ligand sparteine. The enantioenrichment remained high on removing the tert-butoxycarbonyl (Boc) protecting group. The intermediate organolithium undergoes ring opening to an enamine. The kinetic resolution was extended to give enantiomerically enriched substituted 1,2,3,4-tetrahydroquinoxalines and was applied to the synthesis of an analogue of the antibiotic levofloxacin that was screened for its activity against the human pathogen Streptococcus pneumoniae.

Remarkable Ligand Effect on Rh-Catalyzed C-H-Active [3 + 2] Annulation of Ketimines and Alkynes

Externally added ligands were first found to have a significant impact on the Rh-catalyzed C-H-active [3 + 2] annulation of ketimines and alkynes. Olefin ligands have shown remarkable promotion effect for this reaction. The olefin promoted the reaction by

Rhodium-Catalyzed Spiro Indenyl Benzoxazine Synthesis via C-H Activation/Annulation of 3-Aryl-2H-Benzo[b][1,4]oxazines and Alkynes

The rhodium (III)-catalyzed annulation of 3-Aryl-2H-Benzo[b][1,4]oxazines with alkynes via C–H activation has been developed. This reaction afforded a series of spiro indenyl benzoxazine in high yields under mild reaction condition with good functional group tolerance.

Enantioselective Biocatalytic Reduction of 2 H-1,4-Benzoxazines Using Imine Reductases

A biocatalytic reduction of 2H-1,4-benzoxazines using imine reductases is reported. This process enables a smooth and enantioselective synthesis of the resulting cyclic amines under mild conditions in aqueous media by means of a catalytic amount of the cofactor NADPH as hydride source as well as glucose as the reducing agent used in stoichiometric amounts for in situ cofactor recycling. Several substrates were studied, and the 3,4-dihydro-2H-1,4-benzoxazines were obtained with up to 99% ee. In addition, the efficiency of this reduction process based on imine reductases as catalysts has been demonstrated for one 2H-1,4-benzoxazine on an elevated laboratory scale running at a substrate loading of 10 g L-1 in the presence of a tailor-made whole-cell catalyst.

A Rhodium-Catalyzed [3 + 2] Annulation of General Aromatic Aldimines/Ketimines and N-Substituted Maleimides

A new class of rhodium-catalyzed, C-H activation triggered [3 + 2] annulations of aromatic aldimines or ketimines and maleimides was reported in this study. A broad scope of general imines without electron-withdrawing groups were successfully activated an

A Rhodium-Catalyzed [3 + 2] Annulation of General Aromatic Aldimines/Ketimines and N-Substituted Maleimides

A new class of rhodium-catalyzed, C-H activation triggered [3 + 2] annulations of aromatic aldimines or ketimines and maleimides was reported in this study. A broad scope of general imines without electron-withdrawing groups were successfully activated an

Synthesis method of polysubstituted quinoline

The invention discloses a synthesis method of polysubstituted quinolone. The method comprises the step: in an oxygen-containing atmosphere, enabling acetophenone, an aniline compound and dimethyl sulfoxide to react in a pot in the presence of an iron salt and/or ferrous salt catalyst so as to obtain the polysubstituted quinolone. By adopting the method disclosed by the invention, the variety of quinolone derivatives is enriched and more intermediates are provided for medicine synthesis; the synthesis method has the advantages of wide raw material sources, simple steps, moderate reaction conditions and high yield and industrial production is facilitated.

Searching for Novel Inhibitors of the S. aureus NorA Efflux Pump: Synthesis and Biological Evaluation of the 3-Phenyl-1,4-benzothiazine Analogues

Bacterial resistance to antimicrobial agents has become an increasingly serious health problem in recent years. Among the strategies by which resistance can be achieved, overexpression of efflux pumps such as NorA of Staphylococcus aureus leads to a sub-lethal concentration of the antibacterial agent at the active site that in turn may predispose the organism to the development of high-level target-based resistance. With an aim to improve both the chemical stability and potency of our previously reported 3-phenyl-1,4-benzothiazine NorA inhibitors, we replaced the benzothiazine core with different nuclei. None of the new synthesized compounds showed any appreciable intrinsic antibacterial activity, and, in particular, 2-(3,4-dimethoxyphenyl)quinoline (6 c) was able to decrease, in a concentration-dependent manner, the ciprofloxacin MIC against the norA-overexpressing strains S. aureus SA-K2378 (norA++) and SA-1199B (norA+/A116E GrlA).

Method for preparing 3,4-dihydrobenzo[b][1,4]oxazine derivatives

The invention provides a method for preparing 3,4-dihydrobenzo[b][1,4]oxazine derivatives. The method comprises the following step: carrying out reduction reaction on [b][1,4]oxazines in the presence of hydrogen gas by using B(C6F5)3 as a catalyst to obtain the mixture containing the 3,4-dihydrobenzo[b][1,4]oxazines disclosed as Formula I. Benzo[b][1,4]oxazines in different structures are used as a substrate to synthesize the benzo[b][1,4]oxazines at high yield by using the B(C6F5)3 as the catalyst. The method has the advantages of cheap and accessible raw materials, high reaction activity, no participation of transition metals and wide substrate application range, and has huge industrialization potential.

A metal-free hydrogenation of 3-substituted 2H-1,4-benzoxazines

A metal-free hydrogenation of 3-substituted 2H-1,4-benzoxazines has been successfully realized with 2.5 mol% of B(C6F5)3 as a catalyst to furnish a variety of 3,4-dihydro-2H-1,4-benzoxazines in 93-99% yields. Up to 42% ee was also achieved for the asymmetric hydrogenation with the use of a chiral diene and HB(C6F5)2.