2-Methoxy-3-methyl-4-pyrimidine

Reduction of 3-benzyl-8-chloro-4-oxo-4//-pyrido[l,2- ]pyrimidine-2-carboxylate <2004W004/064741> and 2-methyl-4-oxo-4//-pyrido[l,2-tf]pyrimidine-3-carboxylate <2003T4123> with DIBAL-H afforded 2- and 3-formyl derivatives, respectively. Reduction of /V-(4-fluorobenzyl)-3-hydroxy-8-[methoxy(methyl)amino]-4-oxo-6,7,8,9-tetra-hydro-4//-pyrido[l,2- ]pyrimidine-2-carboxamide with Zn-dust in aqueous AcOH afforded the 8-methylamino derivative, which was acylated with AcOH in the presence of Hiinig s base, HOBt, and l-(3-dimethylaminopro-pyl)-3-ethylcarbodiimide-HCl <2004W004/058756>. 3-(Perhydropyrido[l,2- ]pyrimidin-2-yl)propylamine was obtained by catalytic hydrogenation of 2-(perhydropyrido[l,2- ]pyrimidin-2-yl)propionitrile over a Pt02 catalyst <2003FRP1275647>. 

Hydrogenation of 4-cyano-4-(methoxymethoxy)butyrate in the presence of HO(CH2)2NH2 and (CH2NH2)2 over a Pd/C catalyst gave a mixture of diastereomers of 9-(methoxymethyl)perhydropyrido[2,l-A [l,3]oxazin-6-ones and 5-(methoxymethyl)-l-(3-hydroxypropyl)piperid-2-one, and furthermore a diastereomeric mixture of 9-(methoxy-methyl)perhydropyrido[l,2- ]pyrimidin-6-ones <2003ASC483>. Reaction of 535 with TsOH in the presence of H20, followed by treatment with saturated aqueous NaHC03, yielded a mixture of 536 and 537 (Equation 90) <1995JOC2989>. 

Pyrimidin l,3-Di-tert.-butyl-4-oxo-hexahydro- VII/4, 150 Pyrrolidin 2-(Methoxy-methyl)-l-(1,2,2-trimethyl-propylidenami-no)- E21a, 996 (Keton + H2N-NR2)... 

To mimic more closely the methoxy substituted pyrimidine and triazine sulfonylureas, the preparation of triazoles analogous to 18 was targeted in which at least one of the methyl groups is replaced by alkoxy or alkylthio groups. 

Cyclopent-2-en-l-one, 2-hydroxy-3-methyl-synthesis, 3, 693 Cyclopentenone, 4-methoxy-formation, 1, 423 Cyclopenthiazide as diuretic, 1, 174 Cyclopent[2,3-d]isoxazol-4-one structure, 6, 975 Cyclophane conformation, 2, 115 photoelectron spectroscopy, 2, 140 [2,2]Cyclophane conformation, 2, 115 Cyclophanes nomenclature, 1, 27 Cyclophosphamide as pharmaceutical, 1, 157 reviews, 1, 496 Cyclopiloselloidin synthesis, 3, 743 Cyclopolymerization heterocycle-forming, 1, 292-293 6H-Cyclopropa[5a,6a]pyrazolo[l,5-a]pyrimidine pyrazoles from, 5, 285 Cydopropabenzopyran synthesis, 3, 700 Cyclopropachromenes synthesis, 3, 671 Cyclopropa[c]dnnolines synthesis, 7, 597 Cyclopropanation by carbenes... 

Mepirizole — see also Pyrimidine, 4-methoxy-2-(5-methoxy-3-methylpyrazol-l-yl)-6-methyl-metabolism, 5, 301, 302 Mepitiostane, 7, 182, 183 Mepivacaine... 

Pyrimidine, 4-fluoro-2-isopropyl-synthesis, 3, 140 Pyrimidine, 4-fluoro-2-methoxy-synthesis, 3, 140 Pyrimidine, 4-fluoro-2-methyl-NMR, 3, 63 Pyrimidine, halo-aleoholysis, 3, 100 aminolysis, 3, 99 as antitumour agents, 3, 152 bipyrimidines from, 3, 103 Buseh biaryl synthesis, 3, 103 hydrolysis, 3, 101... 

Pyrimidine, 4-methoxy-2-( 5-methoxy-3-methylpyrazol-I-yl)-6-methyl-analgesic activity, 5, 294 Pyrimidine, 2-methoxy-5-methyI-rearrangement, 3, 93 Pyrimidine, 4-methoxy-6-methyl-N-oxides... 

Pyrimidin-2( 1H )-one, l-methoxy-4,6-dimethyl-synthesis, 3, 112 Pyrimidin-2(lH)-one, 1-methyl-synthesis, 3, 112 Pyrimidin-2(lH)-one, 4-methyl-acidic p/fa, 3, 60 reactions, 3, 89... 

The pyrimidine compounds are known to undergo a rearrangement of the 0-alkyl derivatives to the iV-alkyl ones. The methoxy derivatives of 1,3,5-triazine display a similar behavior. On applying methyl iodide to 2,4-dimethoxy-l,3,5-triazine one of the methyl groups is shifted giving rise to l-methyl-4-methoxy-derivative (22). This compound was also obtained by methylation of 4-methoxy-2-oxo-1,2-dihydro-1,3,5-triazine (18) with diazomethane. At higher temperature (100°C) in presence of methyl iodide a shift of both methyl groups takes place and methiodide is formed simultaneously (23). Similarly,... 

The solid state structures of anhydro-(3-methy - and 3-phenyl-2-hydroxy-4-oxo-47/-pyrido[l,2-n]pyridinium)hydroxides, 2-methoxy-3-methyl-47/-and 2-(2-pyridylamino)-47/-pyrido[l, 2-n]pyrimidin-4-ones were established by X-ray diffraction analysis. The amide type N(5)-C(4)-0 bonds are unusually long (144-149 pm) showing no sign of an amide type conjugation. 

The side chain hydroxy group of 3-(2-hydroxyethyl)-2-methyl-9-methoxy-4//-pyrido[l,2-u]pyrimidin-4-one, and that of its 6,7,8,9-tetrahydro derivative was acylated with MeS02Cl in the presence of NEts in CH2CI2 at room temperature (95MIP4, 96MIP2). The hydroxy group of 2-[4-(4-hydro-xybenzoyl)benzyloxy]-3-methyl-4//-pyrido[l, 2-u]-pyrimidin-4-one, its 6-methyl derivative and 2-[4-(4-hydroxybenzoyl)benzylthio]-3-methyl-4//-pyrido[l, 2-u]pyrimidin-4-one was alkylated with 4-(2-chloroethyl)morpholine hydrochloride and 4-picolyl chloride hydrochloride (96EUP733633). 

Methyl-4//-pyrido[l,2-n]pyrimidin-4-ones were also prepared in the reaetion of 2-aminopyridines and ethyl 3-methoxy-2-butenoate in PPA at 80-85 °C for 3h (93MI2). 

Substituted pyrimidine N-oxides such as 891 are converted analogously into their corresponding 4-substituted 2-cyano pyrimidines 892 and 4-substituted 6-cya-no pyrimidines 893 [18]. Likewise 2,4-substituted pyrimidine N-oxides 894 afford the 2,4-substituted 6-cyano pyrimidines 895 whereas the 2,6-dimethylpyrimidine-N-oxide 896 gives the 2,6-dimethyl-4-cyanopyrimidine 897 [18, 19] (Scheme 7.6). The 4,5-disubstituted pyridine N-oxides 898 are converted into 2-cyano-4,5-disubsti-tuted pyrimidines 899 and 4,5-disubstituted-6-cyano pyrimidines 900 [19] (Scheme 7.6). Whereas with most of the 4,5-substituents in 898 the 6-cyano pyrimidines 900 are formed nearly exclusively, combination of a 4-methoxy substituent with a 5-methoxy, 5-phenyl, 5-methyl, or 5-halo substituent gives rise to the exclusive formation of the 2-cyanopyrimidines 899 [19] (Scheme 7.6). The chemistry of pyrimidine N-oxides has been reviewed [20]. In the pyrazine series, 3-aminopyrazine N-ox-ide 901 affords, with TCS 14, NaCN, and triethylamine in DMF, 3-amino-2-cyano-pyrazine 902 in 80% yield and 5% amidine 903 [21, 22] which is apparently formed by reaction of the amino group in 902 with DMF in the presence of TCS 14 [23] (Scheme 7.7) (cf. also Section 4.2.2). Other 3-substituted pyrazine N-oxides react with 18 under a variety of conditions, e.g. in the presence of ZnBr2 [22]. 

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