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3- Methoxy-l,2,4-triazine 2-oxide

Derivatives of 3-oxo-l,2,4-triazine 1-oxide undergo alkylation with various alkylating agents. Thus the reaction of 3-methoxy-l,2,4-triazine 1-oxide 20 with 2,3,5-tii-(9-benzoyl-/3-D-ribofuranosyl bromide, followed by the removal of the benzoyl protection with sodium methoxide, leads to an abnormal nucleoside 4-(/3-D-iibofuranosyl)-l,2,4-triazin-3(4//)-one 1-oxide 21 (73JOC3277). [Pg.269]

A number of 1,2,4-triazines such as the parent compound, the 3-methylthio, 3-methoxy and 3-amino-6-bromo derivatives add ammonia in liquid ammonia at -44 °C to the N(4) —C(5) bond to give adducts of type (lOl), as was shown by XH and 13CNMR spectroscopy. No reaction was observed with 3-methoxy-l,2,4-triazine 1-oxide (71), other 3-amino-l,2,4-triazines, or compounds with a substituent in the 5-position. As was shown using lsN-enriched ammonia, an equilibrium between the covalent addition products (101) and the open-chain isomers (102) does not occur (78RTC273). [Pg.401]

Methoxy-l,2,4-triazine 1-oxide (93) with methyl iodide in methanol at room temperature for 10 days produced 2-methyl-1,2,4-triazin-3-one 1-oxide (94). 3-Methoxy-l,2,4-triazine 2-oxide (95)... [Pg.525]

Unsubstituted 1,2,4-triazine 1-oxides 80 react with benzyne to give 1,3-benzoxazepines 81 and or triazines via the unisolable 1,3-dipolar cycloadducts, whereas the 6-substituted compound 5,6-dimethyl-3-methoxy-l,2,4-triazine 1-oxide affords only the relatively stable 1,5-shift product 82. Heating 82 yields the novel 1,3,5,6-benzoxatri-azoline 83 and 2,3-dimethylbenzofuran <96H(43)2091>. [Pg.287]

The methoxy group is replaced in the reaction of 3-methoxy-5-phenyl-1,2,4-triazine 1-oxide 46 with ammonia, resulting in 3-amino-5-phenyl-l,2,4-triazine 1-oxide 47. The treatment of 3-methoxy-l,2,4-triazine 1-oxide 20 with hydrazine leads to 3-hydrazino-l,2,4-triazine 1-oxide 48 (71JOC787). [Pg.273]

A similar migration of the methyl group was found in 3-methoxy-l,2,4-triazine 2-oxides 18 under the same conditions to afford the 2-methoxy-1,2,4-triazin-3(2/f)-one 125 (84TL1677). [Pg.291]

The reaction of 4-methoxy-3-nitropyridines 129 with guanidine under similar conditions results in 3-aminopyrido[3,4-e]-l,2,4-triazine 1-oxides 130 (76MI). [Pg.292]

Oxidation of 3-methoxy- or 3-phenoxy-1,2,4-triazines (228) with perbenzoic acid converted them into the appropriate 1-oxides (229) (71JOC787). Peracid treatment of 1,2,4-triazin-3-ones with an unsubstituted 5-position (84 R5 = H) gave l,2,4-triazine-3,5-diones (182) (69JHC403), while 5-substituted l,2,4-triazin-3-ones (84) afforded the appropriate 1-oxides (230) (66JOC3914). 3-Amino-l,2,4-triazines with an unsubstituted (86a) or a monosubstituted amino group (86b) were oxidized by peracids to give the 2-oxides (231), while the 3-dialkylamino compounds (86c) afforded the 1-oxides (232) (77JOC546). [Pg.410]

The base and acid hydrolysis of. syrw-triazine mononitriles has been studied <06CHE642>. The potassium salt of 2-amino-4-methoxy-6-dinitromethyl-l,3,5-triazines 30 with N204 afforded the nitroformaldoximes 31 and the 1,2,5-oxadiazole iV-oxides 32 <06CHE1096> <06CHE557>. [Pg.418]

One obvious synthetic route to isoxazoles and dihydroisoxazoles is by [3+2] cycloadditions of nitrile oxides with alkynes and alkenes, respectively. In the example elaborated by Giacomelli and coworkers shown in Scheme 6.206, nitroalkanes were converted in situ to nitrile oxides with 1.25 equivalents of the reagent 4-(4,6-di-methoxy[l,3,5]triazin-2-yl)-4-methylmorpholinium chloride (DMTMM) and 10 mol% of N,N-dimethylaminopyridine (DMAP) as catalyst [373], In the presence of an alkene or alkyne dipolarophile (5.0 equivalents), the generated nitrile oxide 1,3-dipoles undergo cycloaddition with the double or triple bond, respectively, thereby furnishing 4,5-dihydroisoxazoles or isoxazoles. For these reactions, open-vessel microwave conditions were chosen and full conversion with very high isolated yields of products was achieved within 3 min at 80 °C. The reactions could also be carried out utilizing a resin-bound alkyne [373]. For a related example, see [477]. [Pg.238]

The most used reaction of A -aminopyrazoles is their oxidation to 1,2,3-triazines <93LA367>. The mechanism of this reaction has been studied by Boulton <86JCS(P1)1249> using N labeling on the amino group one of the examples described is the rearrangement of l-amino-3-methoxyindazole into 4-methoxy-1,2,3-benzotriazine,... [Pg.53]


See other pages where 3- Methoxy-l,2,4-triazine 2-oxide is mentioned: [Pg.589]    [Pg.590]    [Pg.591]    [Pg.589]    [Pg.590]    [Pg.591]    [Pg.651]    [Pg.394]    [Pg.415]    [Pg.160]    [Pg.348]    [Pg.394]    [Pg.415]    [Pg.402]    [Pg.417]    [Pg.402]    [Pg.417]    [Pg.526]    [Pg.966]    [Pg.468]    [Pg.721]    [Pg.238]    [Pg.345]   


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5- -l,2,4-triazine

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