- Iron- or Zinc-Mediated Synthetic Approach to Enantiopure Dihydroquinoxalinones
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A general and efficient synthesis of enantiopure dihydroquinoxalinones has been developed using naturally occurring amino acids as starting materials. The reductive cyclization of N-(o-nitroaryl)amino esters was performed by using iron and zinc metal under mild conditions in a water/ethyl acetate mixture. The corresponding dihydroquinoxalinones were obtained in moderate to high yields and high enantiomeric purity, among which 7 new compounds were unprecedented in the literature.
- Li, Dazhi,Ollevier, Thierry
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supporting information
p. 1273 - 1280
(2019/01/04)
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- Copper-catalyzed C-N coupling reactions of aryl halides with α-amino acids under focused microwave irradiation
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We have developed an efficient method for the preparation of enantiopure N-aryl-α-amino acids via copper-catalyzed N-arylation of α-amino acids and aryl halides under microwave irradiation. This protocol only needs less than 30 min to obtain the products,
- Narendar, Nasani,Velmathi, Sivan
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scheme or table
p. 5159 - 5161
(2009/12/05)
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- N-(2-nitrophenyl)proline: An intramolecular hydrogen bond forming reagent for the determination of the absolute configuration of primary amines
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N-(2-Nitrophenyl)proline (2-NPP) amides of primary amines have a conformational preference for intramolecular hydrogen bonding. Because of the strong and selective anisotropic effects on the amine substituents, the absolute configuration of α-chiral primary amines can be assigned by comparing the 1H chemical shifts of diastereomeric 2-NPP amides.
- Ahn, Hee Choon,Choi, Kihang
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p. 3853 - 3855
(2008/02/12)
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- Synthesis of tri- and tetracyclic condensed quinoxalin-2-ones fused across the C-3 - N-4 bond
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We have studied the preparation of some fused quinoxalinones by Stevens rearrangement of a spiro-quinoxaline-derived ammonium ylide or by treatment of N-(2,4-dinitrophenyl)-and N-(2-nitrophenyl)imino acids with different reducing agents. We have reinvestigated and clarified some related processes found in the literature starting from imino acids derivatives. Additional reactions of the fused quinoxalinones, as well as the useful dehydrogenation/decarboxylation of some easily available 1-arylindoline-2-carboxylic acids to the corresponding 1-arylindoles, are also reported. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
- Chicharro, Roberto,De Castro, Sonia,Reino, Jose L.,Aran, Vicente J.
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p. 2314 - 2326
(2007/10/03)
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- Dihydroquinolines as novel n-NOS inhibitors
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Dihydroquinolines have been synthesized and have been shown to be potent n-NOS inhibitors. Selectivity versus e-NOS was increased to approximately 100-fold through appropriate substitution at the benzene ring.
- Jaroch, Stefan,Hoelscher, Peter,Rehwinkel, Hartmut,Suelzle, Detlev,Burton, Gerardine,Hillmann, Margrit,McDonald, Fiona M.
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p. 2561 - 2564
(2007/10/03)
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- Biphenyl derivatives and drug composition
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A biphenyl derivative represented by the following general formula (1) and a pharmaceutically acceptable salt thereof: [In the formula (1), A represents a single bond, —CH2—, —CO—, —CS— or —SO2—; B represents a single bond or —CH2—; R1represents a hydrogen atom, —OH, —NR11R12(wherein R11and R12each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms), —OCOCH3, or a halogen atom; R2represents a hydrogen atom or R1and R2form a group ═O together; R3represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; provided that in the formula, the absolute configuration of the position a may be either R or S]. The compound of the present invention has considerably high safety and efficacy and is useful as, in particular, a vasopressin receptor antagonist.
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- Tetrahydropyrroloquinoxalines and Tetrahydropyrrolopyridopyrazines: Vascular Smooth Muscle Relaxants and Antihypertensive Agents
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A series of tetrahydropyrroloquinoxalines and tetrahydropyrrolopyridopyrazines were synthesized and tested for their ability to relax K+-depolarized aortic smooth muscle and antihypertensive activity.It was shown that compo
- Abou-Gharbia, Magid,Freed, Meier E.,McCaully, Ronald J.,Silver, Paul J.,Wendt, Robert L.
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p. 1743 - 1746
(2007/10/02)
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- Polycyclic Nitrogen Compounds. Part II. Tricyclic Quinoxazolines and Their 4- or 6-Aza Analogues
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1,2,3,3a-Tetrahydro-9-nitropyrroloquinoxalin-4-one and 7,8,9,10-tetrahydro-3-nitropyridoquinoxalin-6-one (V-VI) were reduced and deaminated to give new parent tricyclic quinoxalinone skeletons I-II.The latter compounds were identical with th
- Adegoke, E. A.,Alo, Babajide
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p. 1509 - 1512
(2007/10/02)
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