Chromonics

The fragmentation pattern of isoxazoles on electron impact has been well studied. It has been used as an important tool for the structural assignment of isoxazoles obtained from the reaction of chromones with hydroxylamine 79MI41600, 77JOC1356). For example, the structures of the isoxazoles (387) and (388) were assigned on the basis of their fragmentation patterns. Ions at mje 121 (100%) and mje 93 (19.8%) were expected, and indeed observed, for the isoxazole (388), and an ion at mje 132 (39.5%>) was similarly predicted and observed for the isoxazole (387). [Pg.79]

The reaction of hydroxylamine with 2-substituted chromones (392) where R = Me, Ph (76MI41601) or CO2H (79MI41600) gave exclusively 5-(o-hydroxyphenyl)isoxazoles (393). [Pg.79]

Benzofurans, 4, 531-597, 657-712 chroman synthesis from, 3, 785 chromene synthesis from, 3, 753 chromone synthesis from, 3, 828 CNDO, 4, 536... [Pg.548]

H-l-Benzopyran-4-ones — see Chromones 4H-l-Benzopyran-4-ones, 2-phenyl — see Flavones Benzopyranopyrazoles synthesis, S, 317, 341 Benzopyrano[4,3-c]pytazol-4-one synthesis, 3, 712 Benzopyrano[4,3-6]pyridine synthesis, 3, 712 Benzopyrano[4,3-ii]pyrimidine synthesis, 3, 712 Benzopyrans nomenclature, 1, 23 pyrylium salt synthesis from, 3, 873 reactions... [Pg.551]

Benzopyrylium perchlorate, 3-ethyI-reduction, 3, 662 Benzopyrylium salts C NMR, 3, 590 chromene synthesis from, 3, 756 chromone synthesis from, 3, 829 electrophilic substitution, 2, 49 mass spectra, 3, 618 reactions... [Pg.552]

Benzoxepin-4-carbaldehyde, dihydro-from chromones, 3, 713 Benzoxepin-4(3H)-one from isochromanone, 3, 726 [l]Benzoxepino[3,4-d]selenazoles synthesis, 6, 345 Benzoxepins... [Pg.567]

Chromone, 2-alkylamino-5,8-dimethoxy-synthesis, 3, 717 Chromone, 2-amino-aromaticity, 3, 714 tautomerism, 3, 644... [Pg.581]

Chromone, 2-amino-3-chloro-synthesis, 3, 713 diacetate, 3, 714 Chromone, 3-aroyl-photochemistry, 3, 695 Chromone, 2-benzhydryl-3-benzoyl-photoenolization, 3, 695 Chromone, 3-benzoyl-2-benzyl-photoenolization, 3, 695 Chromone, 3-benzoyl-2-methyl-synthesis, 3, 823 Chromone, 2-benzyl-in photochromic processes, 1, 387 Chromone, 3-benzyl-photolysis, 3, 695 Chromone, 3-bromo-synthesis, 3, 828 Chromone, 3-bromoacetyl-ring opening, 3, 713 Chromone, 3-bromo-2-methyl-reactions... [Pg.581]

Chromone, 2,3-dichloro-7-methoxy-synthesis, 3, 825 Chromone, dihydromass spectra, 2, 23 Chromone, 3,5-dihydroxy-2-methyl-selective methylation, 3, 716 Chromone, 5,7-dihydroxy-2-methyl-prenylation, 3, 716 Chromone, 3,7-dimethoxy-2-methyl-reactions... [Pg.581]

Chromone, 5-hydroxy-2-methyl-biosynthesis, 3, 876 Chromone, 6-hydroxy-2-methyl-reactions... [Pg.581]

Chromone, 7-hydroxy-2-methyl-bromination, 3, 707 Chromone, 3-hydroxymethylene-synthesis, 3, 821... [Pg.582]

Chromone, 3-hydroxymethyl-8-methoxy-antiallergic activity, 3, 707 Chromone, 7-methoxy-chlorosulfonation, 3, 708 Chromone, 7-methoxy-2-methyl-chloromethylation, 3, 708 Chromone, 2-methyl-chloromethylation, 3, 697 halogenation, 3, 709 IR spectra, 3, 596 mass spectra, 3, 613 oxidation, 3, 709 reactions... [Pg.582]

Chromone, N-methyltetrazol-5-yl-antiallergic activity, 5, 836 Chromone, 3-nitro-reactions... [Pg.582]

Chromone, 3-(tetrazol-5-yl)-antiallergic activity, 5, 836 degradation, 5, 815 Chromone, 3,5,7-trimethoxy-2-methyl-photolysis, 3, 695... [Pg.582]

Chromone-2-carbaldehyde, 3-methyl-synthesis, 3, 709 Chromonecarbaldehydes Knoevenagel condensation, 3, 711 Chromone-3-carbaldehydes mass spectra, 3, 615 oxidation, 3, 709 reactions, 3, 712 Schiff bases, 3, 712 synthesis, 3, 821 Chromone-2-carbonyl chloride Grignard reaction, 3, 711 Chromonecarboxamide, N-tetrazolyl-antiallergic activity, 3, 707 Chromone-2-carboxylic acid, 3-chloro-ethyl ester... [Pg.582]

Chromone-2-carboxylic acid, 8-cyano-6-methyl-ethyl ester... [Pg.582]

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