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2-Amino-3-cyano-5- pyrazine

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]. [Pg.152]

The conversion of DAMN into 2,3-dicyanopyrazines substituted in the 5-and 6-positions with various combinations of amino, cyano, chloro, and hydroxyl groups will be described in this section along with transformations of these initially formed materials into a variety of other multifunctional and fused ring pyrazines. [Pg.15]

Pyrazine 1-oxide and 3-amino- and 3-chloropyrazine 1-oxide with tosyl chloride in the presence of pyridine gave 2-pyridiniopyrazine chloride (14) and 2-amino- or 2-chloro-3-pyridiniopyrazine chloride, respectively and 3-methoxycarbonyl(or morpholinocarbonyl or cyano)pyrazine 1 -oxide treated similarly gave 2-methoxy-... [Pg.210]

Treatment of diphenylacetonitrile in toluene with sodium amide and 2-chloro-pyrazine gave 2-(C-cyano-C,C-diphenylmethyl)pyrazine (1021), and 2-vinylpyrazine with phenylacetonitrile and sodium heated at 120-130° for 10 minutes gave 2-(3 -cyano-3 -phenylpropyl)pyrazine (731). 2-Amino-5-bromomethyl-3-cyano-pyrazine with sodium hydride and methyl cyanoacetate in tetrahydrofuran formed the dialkylated product (56) (1031). 2-Amino-3-mercapto-5,6-dimethylpyrazine in methanol with potassium hydroxide and chloroacetonitrile gave 2-amino-3-cyanomethyIthio-5,6-dimethylpyrazine (1229), and 2-carboxypyrazine refluxed with chloroacetonitrile and triethylamine in ethyl acetate for 45 minutes gave the cyanomethyl ester (1317). 2-Hydroxy 5-methyl-3-propylpyrazine with cyanogen halides in aqueous sodium hydroxide-dimethylformamide at 0-5° gave l-cyano-5-methyl-2-oxo-3-propyl-l, 2-dihydropyrazine (1123). [Pg.289]

Iminothioethers have similarly been prepared from nitriles. 2-Amino-3-cyano-pyrazine with sodium methanethiolate (other alkanethiolates reached similarly) in ethanol gave 2-amino-3-(Cimino-C-methylthiomethyl)pyrazine (60) (792, 878, 1075) [which with guanidine hydrochloride and sodium methoxide in methanol gave 2-amino-3-(C-guanidino-C-iminomethyl)pyrazine (878)] 2-amino-5-chloro-3-cyanopyrazine with methanethiol and sodium hydroxide in methanol gave 2-amino-5-chloro-3-(C-imino-C-methylthiomethyl)pyrazine (877, 1218) [which with... [Pg.291]

The oxidations of 2-amino-3-cyanopyrazine 1-oxides to the 1,4-dioxides are described in Section VIII.3A(4) and deoxygenations of some 2-amino-3-cyano-pyrazine 1-oxides and 1,4-dioxides with phosphorus trichloride or sodium dithionite in Section VIII.3C(4). Deoxygenation and chlorination of aminocyanopyrazine 1-oxides are reported in Section V.IG, and deoxygenation and acetoxylation or alkoxylation of 2-amino-3-cyano-5-methylpyrazine 1,4-dioxide in Section VIII.3C(5). Hydrolysis of cyanopyrazine Y-oxides to carbamoylpyrazine Af-oxides are given in Section 10A(3) and ring closure reactions of 2-amino-3-cyanopyrazine 1-oxides to pteridine 8-oxides in Section V11I.3C(3). [Pg.308]

Vercek and co-workers described an effective approach to some 3-cyano-4-amino[l,2,3]triazolo[l,5-tf]pyrazines starting from the N-substituted triazole derivatives 396 <2002H(56)353>. This compound when treated either with acetic acid or triethylamine gave rise to the ring-closed products 397 in acceptable yield (55-66%). [Pg.726]

An unequivocal synthesis of (637), protected as its A-2 -acetyl derivative (643), was successfully accomplished as shown in Scheme 3.140 [40]. Pyruval-dehyde dimethylacetal was first converted into its enamine (108). Condensation of (108) with the O-tosyl derivative of oximinomalononitrile gave the azadiene (638), which was converted to 2-amino-3-cyano-6-dimethoxymethyl-pyrazine (639) with ammonia. This latter compound was condensed with guanidine and the product (640) hydrolyzed first with base (to remove the 4-amino group) and then with acid to give pterin-7-carboxaldehyde (641). Acetylation of (641) followed by condensation with di-t-butyl p-aminobenzoyl-glutamate (235), reduction and hydrolysis gave (643). [Pg.208]

Just as pyrazine. V-oxides may be converted into C-halogeno- (Section 4.1.3) or C-acyloxypyrazines (Section 5.5.2.3), so they can afford C-amino-, C-azido-, C-cyano-, or C-alkylthiopyrazines, although such reactions are not well developed yet. The following examples will illustrate such procedures as used in recent literature ... [Pg.237]

Pyrazinecarbaldehydes can of course be recovered from their derivatives for example, the acetal, methyl 6-amino-5-cyano-3-diethoxymethyl- (249), gave methyl 6-amino-5-cyano-3-formyl-2-pyrazinecarboxylate (250) in 85% yield by selective hydrolysis in dilute hydrochloric acid at 20°C during 12 h 773 likewise, the extranu-clear acetal, 2-(3,3-diethoxypropyl)-3-ethoxycarbonylmethylpyrazine, gave 2-ethoxycarbonylmethyl-3-(2-formylethyl)pyrazine in 92% yield on hydrolysis in aqueous alcoholic hydrochloric acid at 35°C during 2 h.1249... [Pg.336]

Amino-5-chloro-6-thioxo-1,6-dihydro-2-pyrazinecarbohydrazide 3-Amino-6-chloro-5-thioxo-4,5-dihydro-2-pyrazinecarbohydrazide 3-Amino-6-cyano-5-methoxy-2-pyrazinecarboxamide 3-Amino-6-cyano-5-methoxy-2-pyrazine-carboxylic acid... [Pg.360]


See other pages where 2-Amino-3-cyano-5- pyrazine is mentioned: [Pg.318]    [Pg.318]    [Pg.318]    [Pg.134]    [Pg.147]    [Pg.245]    [Pg.280]    [Pg.291]    [Pg.266]    [Pg.36]    [Pg.125]    [Pg.768]    [Pg.391]    [Pg.259]    [Pg.126]    [Pg.135]    [Pg.136]    [Pg.130]    [Pg.82]    [Pg.65]    [Pg.303]    [Pg.829]    [Pg.34]    [Pg.37]    [Pg.125]    [Pg.993]    [Pg.768]    [Pg.93]    [Pg.246]    [Pg.151]    [Pg.125]    [Pg.720]    [Pg.360]    [Pg.360]    [Pg.226]   
See also in sourсe #XX -- [ Pg.147 , Pg.148 , Pg.257 , Pg.299 , Pg.300 ]




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