5.6.7.8- Tetrahydro-2 -quinoxalinone

Cyclohexanedione (322) and 2-amino-A -hydroxyacetamide (323) gave 1-hydroxy-5,6,7,8-tetrahydro-2(17/)-quinoxalinone (324) (Et0H-H20, minimal... [Pg.44]

Benzenediamine (358) and 5-(l,2-dihydroxyethyl)tetrahydro-2,3,4-furane-trione (359) (prepared in situ by oxidation of ascorbic acid with p-benzoqui-none) gave either 3-(2,3,4-trihydroxybutyryl)-2(17i)-quinoxalinone (360)... [Pg.49]

Methyl-2(17/)-quinoxalinone (109) and 2-methylacrylonitrile (110) gave the photoadduct, l,2a-dimethyl-3-oxo-2,2a,3,4-tetrahydro-l//-azeto[ 1,2-u]quinoxa-line-l-carbonitrile (111) (CH2CI2, MeOH, hv, N2, <15 h >95%) also analogs using significantly electron-deficient olefines. [Pg.205]

The A-oxide tautomer, l-hydroxy-5,6,7,8-tetrahydro-2(l//)-quinoxalinone (284) gave l-benzyloxy-5,6,7,8-tetrahydro-2(l//)-quinoxalinone (285) (PhCH2Cl,... [Pg.237]

Chloro-2,2-dimethyl-3-oxo-1,2,3,4-tetrahydro-1 -quinoxalinecarbonyl chloride (89) gave 6-chloro-4-(3,5-dimethylpiperazin-l-yl)carbonyl-3,3-dimethyl-3,4-dihydro-2(177)-quinoxalinone (90) [substrate, EtPr N, CH2CI2 HN(CH2-CHMe)2NHi, 0°C 20°C, 17 h 54%] analogs likewise. " ... [Pg.334]

Benzyloxy-5,6,7,8-tetrahydro-2( l //)-quinoxalinone (208) gave a mixture from which the rearranged isomer, 3-benzyloxy-5,6,7,8-tetrahydro-2(l//)-quinox-alinone (209), and the dealkoxylated product, 5,6,7,8-tetrahydro-2(l//)-qui-noxalinone (210), were isolated (hv, PhH, N2, 90 min 16% and 64%, respectively).618... [Pg.222]

Methyl-3-morpholinoquinoxaline 6-Methyl-3-morpholino-2(177)-quinoxalinone 6-Methyl-2/3-(2-morpholinovinyl)quinoxaline 6-Methyl-7-nitr o-2,3-dioxo, 1,2,3,4-tetrahydro-5-quinoxalinecarboxylic acid 2-Methyl-6-nitro-3-phenylquinoxaline... [Pg.421]

A -Acylation of l,2,3,4-tetrahydro-2-quinoxalinones anchored to Wang resin was achieved by the usual procedure to give 4-acyl derivatives (Equation 16) <1998JOC1172>. [Pg.299]

Ethyl-cr-chlorophenylacetate and o-phenylenediamine in the presence of triethylamine give 3-phenyl-1,2,3,4-tetrahydro-2-quinoxalinone (16), which is oxidized to 3-phenyl-2-quinoxalinone (17) with potassium... [Pg.371]

The infrared spectra of quinoxaline mono- and di-./V-oxides 3-quin-oxalinone 1-oxides, and 1-hydroxyquinoxaline 2,3-diones have been reported, and the ring stretching vibrations and C=0 and N—O stretching frequencies were assigned.267 2-Methyl-6-amino- and 2-methyl-6-nitro-l,2,3,4-tetrahydro-3-quinoxalinones have been examined... [Pg.429]

Tseng and colleagues [58] reported a three-step synthesis of fused tetrahydro-P-carbolinequinoxalinones, solely based on the use of ionic liquids as solvents. Tetrahydro-P-carboline is a central core for many biologically important indole alkaloids, and the moiety of quinoxalinone often exhibits a wide spectrum of biological activities such as being anti-HIV, antihypertensive, and a ligand for a number of protein receptors. As a first step, tryptophan methyl ester was reacted with an aldehyde to form tetrahydro-p-carboline by Pictet-Spengler cyclization that further reacted with l-fluoro-2-nitrobenzene to form iV-aryl-tetrahydro-P-carboline. Intramolecular cyclization upon a reduction reaction in step three provided the desired tetrahydro-P-carbolinequinoxalinones. The entire process was based on the use of 1-n-butyl-... [Pg.482]

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