3.4- dihydroquinoline-2-one

Azetidinones are also formed on photolysis of cis-a-phenyl-cinnamanilide (361), but in addition a small quantity of a cis-trans mixture of 3,4-diphenyl-3,4-dihydroquinolin-2-one (362) was obtained. The yield of quinolinone was considerably increased in the photocyclization of alkyl-substituted acrylanilides.389 The anilide (363) of tiglic acid, for example, was converted into the anilide (364) of angelic acid by photochemical cis-trans isomerism, and into a mixture of cis- and [Pg.103]

A ruthenium-catalyzed intramolecular olefin hydrocarbamoylation for the regiodivergent synthesis of indolin-2-ones and 3,4 dihydroquinolin-2-ones was disclosed by Chang and coworkers (Eq. (7.3)) [8]. The reactions underwent smoothly without requiring external CO atmosphere. In the presence of combined catalysts of Ru3(CO)i2/Bu4NI, a 5-exo-type cyclization proceeds favorably to form indolin-2-ones as a major product in good to excellent yields in DMSO/toluene cosolvent (catalytic system A). When the reaction was conducted in the absence of halide additives in NAf-diniethylacetamide (DMA)/PhCl (catalytic system B), 3,4-dihydroquinolin-2-ones were obtained in major in moderate to high yields via a 6-endo cyclization process. An excellent level of regioselectivity was observed with a variety of substrates to deliver 5-exo- or 6-endo-cyclized lactams. 

Two mechanistic pathways, which differed in the way of ruthenium-mediated initial cleavage of formyl C-H or amido N-H bond, were proposed for the catalytic cycle. As shown in Scheme 7.3, an irreversibly cleavage of formyl C-H bond by the active ruthenium complex was followed by reversible insertion of the olefin into the Ru-H bond, which afforded either six-membered or seven-membered ruthenacycle. After reductive elimination, indolin-2-ones or 3,4-dihydroquinolin-2-one was formed. According to isotopic studies, pathway leading to six-membered lactams is postulated to be less favored. Another cyclization process initiated by Ru-catalyzed oxidative addition of formyl N-H bond (Scheme 7.4) was similar to Carreira s proposal for their hydrocarbamoyla-tion reaction of allylic formamides under similar ruthenium catalysis conditions [7]. The 6-endo cyclization process is proposed to be favored under the catalytic system B. 

N-Arylpiperazin-2-ones, N-arylpiperazin-2,5-diones and N-aryl-3,4-dihydro-quinolin-2(lff)-ones have been synthesized via a microwave-enhanced Goldberg reaction [105]. N-arylation reactions with 4-benzylpiperazin-2-one and 4-benzylpiperazin-2,5-dione performed in the microwave (reflux conditions) were tremendously accelerated in comparison with the same transformations performed under classical heating at reflux (Schemes 103 and 104). The phenylation of 3,4-dihydroquinolin-2(lH)-one under microwave irradiation was also faster but less pronounced. 

Hydrogenation of Quinolines Under Water Gas Shift Conditions and Oxidation of 1,2,3,4-Tetrahydro-quinolines to Hydroxamic Acids 6-Methoxy-1,2,3,4-tetrahydroquinoline and 1-Hydroxy-6-methoxy-3,4-dihydroquinolin-2(1 H)-one. 

Akritopoulou-Zanze I, Whitehead A, Waters JE, Henry RE, Djuric SW (2007) Synthesis of substituted 3,4-dihydroquinolin-2(lH)-one derivatives by sequential Ugi/acrylanilide [6pi]-photocyclizations. Tetrahedron Lett 48 3549-3552... 

Keywords (V-methyl cyclohex-1-enylanilide, inclusion crystal, [2+2]poto-cycloaddition, 3,4-dihydroquinolin-2( 177)-one... 

Tanaka, K., Kakinoki, O., and Toda, F. (1992) Control of the stereochemistry in the photocydisation of acrylanilides to 3,4-dihydroquinolin-2(lH)-ones. Delicate dependence on the host compound. Journal of the Chemical Society, Chemical Communications, 1053-1054. 

Photocyclization of acrylanilide 21 to 3,4-dihydroquinolin-2(l//)-one 22 was applied in alkaloid synthesis, but enantiocontrol was unsuccessful in solution [46]. Solid-state photolysis of 21 in the 1 1 inclusion complexes with optically active host compounds 6a-c gave 22 in almost perfect optical yields (Scheme 5) [34,47]. X-ray crystallographic analysis revealed that the configuration of the photocyclization products depended on slightly different lattice structures, which were controlled by the host molecules. 

Cilostazol has been used to treat intermittent claudication in individuals widi peripheral vascular disease. A similar molecule as cilostazol may have the risk of death in patients with congestive heart failure. The synthesis of cilostazol contains a 1,3-dipolar addition for the construction of the tetrazole ring, and the resulting tetrazole was coupled with 6-hydroxy-3,4-dihydroquinolin-2(l//)-one with the aide of potassium hydroxide. ... 

A mixture of methyl 6-chloro-3,4-epoxy-4-phenyl-3,4-dihydroquinolin-2(lH)-one-3-carboxylate, NH4CI and dimethylformamide refluxed 20 min. 5-chloro-3-phenyloxindole. Y 94%. F. e. s. A. Walser, A. Szente and J. Hellerbach, J. Org. Chem. 38, 449 (1973). 

The Rh-catalyzed cascade conjugate addition/cycUzation of olefins 70 bearing two electrophilic sites and a pendant nucleophile with organoboroxines was reported by Park and Youn (Scheme 5.48) [46]. The procedure afforded a variety of N- and 0-heterocycles 71, such as 3,4-dihydroquinolin-2(l//)-ones, 3,4-dihydrocoumarins, and pyrrolidin-2-ones. 

To a solution of 4-hydroxy-2-nitroacetanilide (594 mg, 3.03 mmol) in anhydrous MeOH (5 mL) was added boron trifluoride dimethanol complex (0.98 mL, 9.08 mmol). The solution was stirred for 5 h under reflux and subsequently cooled to -15 °C. After addition of t-butyl nitrite (0.36 mL, 3.03 mmol), the solution was stirred for 20 min while raising the temperature to 0 °C. To the reaction mixture was added methyl acrylate (0.41 mL, 4.54 mmol) and Pd(OAc)2 (34 mg, 5 mol%). The solution was stirred overnight at ambient temperature. After addition of activated charcoal (85 mg) the reaction mixture was stirred under Hz-atmosphere (1 bar) for 24 h. The reaction was quenched with 1 M HCl-solution (20 mL) and extracted with MTBE (60 mL). The combined organic layers were dried with MgS04, filtered, and concentrated under reduced pressure. The residue was purified by column chromatography (Si02, MTBE) to afford 7-hydroxy-3,4-dihydroquinolin-2(l//)-one (425 mg, 86%) as a colorless solid mp 233 °C. ... 

Phenyl-l,2,3,6-tetrahydropyrido[2,l- ][l,3]thiazino[3,2- ]quinolin-6-ones were prepared by the reaction of 2-mercapto-5-phenyl-l,4-dihydroquinolin-4-ones with 1,3-dihalopropane <1997JAK97/278780>. 7-Acetyl-2-aryl-9-cyano-6-methyl-8-phenyl-3,4-dihydro-277,877-pyrido[2,l- ][l,3]thiazin-4-ones were obtained from 5-acetyl-3-cyano-6-methyl-4-phenyl-l,2,3,4-tetrahydropyridine-2-thione with 3-aryl-2-propenoyl chloride <2002CHE761>. Reaction... 

Ukaji and coworkers [1191] performed the enantioselective addition of or-ganomagnesiums to 3,4-dihydroquinoline N-oxide in the presence of aminoalcohol 2.6 at -78°C. With one exception, the enantioselectivity is in the 80% range. 

Phenyl-l, 2,3,6-tetrahydro[l, 3]thiazino[3,2-n]quinolin-6-ones 90 were prepared in the reactions of 2-mercapto-5-phenyl-l,4-dihydroquinolin-4-ones 103 and 1,3-dihalopropane in 55-79% yields (97JAP(K)97/278780). 

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