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1 -Benzyl-3- -pyrazinone

The authors have also elaborated a microwave-enhanced one-pot procedure [90] for the Huisgen 1,3-dipolar cycloaddition reaction. In a typical procedure, a pyrazinone with a triple bond connected to the core via C - O linkage, was reacted with a suitable benzylic bromide and NaNs in presence of the Cu(I) catalyst in a t Bu0H/H20 system under microwave irradiation (Scheme 26). The cycloaddition was found to proceed cleanly and with full regioselectivity. As the azide is generated in situ, this procedure avoids the isolation and purification of hazardous azides, which is especially important when handling the ahphatic ones, which are known to be toxic and explosive in nature. [Pg.287]

Hydroxypyrazines or 2(l//)-pyrazinones are also subject to electrophilic halogenation. A new result is that 1-benzyl- or 1-phenyl-substituted 2(l//)-pyrazinones undergo bromination with NBS or A -iodosuccinimide (NIS) to give the 5-bromo or iodo-2(l//)-pyrazinones in 66-82% yields <2004TL1885, 2005T3953>. [Pg.285]

Benzyl-6-[A -(but-3-ynyl)-A -propionylaminomethyl]-5-chloro-3-methoxy-2(l//)-pyrazinone (48) underwent thermolysis to afford l-benzyl-3-methoxy-7-propio-nyl-5,6,7,8-tetrahydro-l,7-naphthyridin-2(l/7)-one (49) (PhBr, reflux, 2 h 53%, after separation from a second product) the proposed intermediate was not isolated.602... [Pg.151]

Af-Benzyl-/V- (/V-o-methoxyphcnylcarbamoyl)mcthyl glycine (29) underwent de-hydrative cyclization to 4-benzyl-6-hydroxy-l-o-methoxyphenyl-3,4-dihydro-2(1 H)- pyrazinone (30) (l,r-carbonyldiimidazole, THF, 30 —> 65°C, 17 h 83% other reagents gave lower yields).487... [Pg.7]

AH2-Benzylaminoethyl)cyclohexanecarboxamide (115) and chloroacetyl chloride (116) gave l-benzyl-4-cyclohexylformyl-3,4,5,6-tetrahydro-2(l//)-pyrazinone (117) (NaOH, PhCH2Et3NCl, H20—PhH, 20 55°C, 2... [Pg.19]

The only examples of this synthesis employed isoxazolopyrazine substrates that were themselves made from pyrazines. Thus l-benzyl-5,6-dihydro-2(l//)-pyrazi-none 4-oxide (99) underwent addition by ethynylbenzene to give 5-benzyl-2-phemi-6,7-dihydro-3a//-isoxazolo[2,3-a]pyrazin-4(5//)-onc (100) (60%), which subsequently underwent ring cleavage by molybdenum hexacarbonyl in wet acetonitrile to afford l-benzyl-3-phenacyl-3,4,5,6-tetrahydro-2(l//)-pyrazinone (101) in 54% yield several analogues were made similarly.1539... [Pg.62]

I -Benzyl-3,6-dichloro-2( l//)-pyrazinonc (127, R = Cl) gave l-benzyl-5-chloro-3-methyl-2(17/)-pyrazinone (127, R = Me) [Me4Sn, Pd(PPh3)4, PhMe, reflux, <5 days residue from evaporation, KF, AcOEt, 20°C, 12 h 81%) or its 3-ethyl ho-mologues (127, R = Et) (Et4Sn, likewise 95%) 391 analogues similarly.391... [Pg.98]

Note The paucity of examples in this category is surprising. l-Benzyl-3,5-dichloro-2(l//)-pyrazinone (131) gave l-benzyl-5-chloro-3-pheny 1-2(1//)-pyrazinone (132) [PhMgBr/Et20 (made in situ), THF, -30°C, 10 min 90%].374... [Pg.99]

Benzyl-5-chloro-3-ethy 1-2(1 //)-pyrazinone gave 1 -benzyl-3-(l-bromoethyl)-5-chloro-2( l//)-pyrazinonc (275) (NBS, Bz202, CCI4, reflux, <6 h 89%).391 Also other examples 29-395-431,513,547,550,676,957,1059,1094,1446, wsi... [Pg.121]

Benzyl-3,5-dichloro-6-phenyl-2(l//)-pyrazinone (91, R = Cl) gave 1-benzyl-5-chloro-3-(o-iodoanilino)-6-phcnyl-2(l//)-pyrazinonc (91, R = NHC6H4I-o) (H2NC6H4I-o, NaH, THF, N2, 20°C, 30 min substrate J, reflux, <5 h 78%) 1607 analogues likewise.1607 Also other examples.481,1063... [Pg.154]

L-Benzyl-6-(l-bromo-2-methylpropyl)-5-chloro-3-phcnyl-2(l//)-pyrazinonc (256, R = Br) gave 6-(l-azido-2-methylpropyl)-l-benzyl-5-chloro-3-phenyl-2(l//)-pyrazinone (256, R = N3) (NaN3, Mc2NCIIO, 60°C, 5 h 62%).53... [Pg.186]

Acetoxy-3,6-dibenzyl-5-methoxypyrazine gave 3,6-di benzyl-5-methoxy-2(l//) -pyrazinone (29) (K2C03, MeOH—H20, reflux, 30 min > 95%) 312 2,5-diace-toxy-3,6-dimethylpyrazine gave 5-hydroxy-3,6-dimethyl-2(l//)-pyrazinone (30) (KHC03, MeOH, reflux, 50 min 53%).1386... [Pg.194]

Acetoxy-5-benzyl-6-diacetylamino-3-methylpyrazine (31) gave 6-amino-5-bcnzyl-3-methyl-2( I //)-pyrazinone (32) (neat H2NNH2, 20°C, 13 h 67% note additional IV-deacetylation).883 Also other examples.304 809 960,1565 1575... [Pg.195]

Methyl-2(lH)-pyrazinone (57) underwent quatemization to l-benzyl-3-methyl-5-oxo-4,5-dihydropyrazinium bromide (58) (PhCH2Br, EtOH, reflux, N2, 24 h 80%) that then gave the zwitterionic base, l-benzyl-5-methylpyrazin-l-ium-3-olate (59) [H20—MeOH, (Amberlite IRA-400, HO ) column 97% this indirect route offers a procedure for N-alkylation on a ring-N that is not adjacent to the oxo substituent] 341 l,5-dimethylpyrazin-l-ium-3-olate was made somewhat similarly.1478... [Pg.199]

Phevalin, 6-benzyl-3-isopropyl-2(l//)-pyrazinone, a Streptomyces sp metabolite antineurodegenerative agent [170713-71-0],1168... [Pg.243]

Amino-5-azido-2,6-pyrazinedicarbonitrile 3-Amino-5-benzoyl-6-bromo-2-pyrazinecarbonitrile 3-Amino-5-benzoyl-2-pyrazinecarbonitrile 3-Amino-5-benzoyl-2-pyrazinecarboxamide 3-Amino-6-benzylamino-2-pyrazinecarboxylic acid 6-Amino-5-benzyl-3-methyl-2(177)-pyrazinone 3-Amino-6-benzylsulfinyl-2-pyrazinecarboxylic acid 3-Amino-6-benzylthio-... [Pg.356]

See other pages where 1 -Benzyl-3- -pyrazinone is mentioned: [Pg.174]    [Pg.122]    [Pg.286]    [Pg.297]    [Pg.293]    [Pg.174]    [Pg.122]    [Pg.237]    [Pg.106]    [Pg.182]    [Pg.183]    [Pg.201]    [Pg.217]    [Pg.222]    [Pg.227]    [Pg.306]    [Pg.352]    [Pg.369]    [Pg.369]    [Pg.369]    [Pg.369]    [Pg.369]    [Pg.369]    [Pg.369]    [Pg.369]    [Pg.369]    [Pg.369]    [Pg.369]    [Pg.369]    [Pg.369]    [Pg.369]    [Pg.369]    [Pg.369]    [Pg.369]   
See also in sourсe #XX -- [ Pg.121 ]



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1 -Benzyl-3.5-dichloro-2 -pyrazinone

1 -Benzyl-5-chloro-3-phenyl-2 pyrazinone

1- Benzyl-2 -pyrazinone 4-oxide

6-Amino-5-benzyl-3-methyl-2 pyrazinone

Pyrazinone

Pyrazinones

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