4-Amino-6-chloro-5-nitropyrimidine

Amino-6-chloro-5-nitropyrimidine Hydrogen sulfide Formic acid Sodium hydroxide... 

BMC863>, <03BMCL2989>. Palladium catalyzed reaction of 4-amino-6-chloro-5-nitropyrimidine 37 with arylacetylenes 38 afforded the corresponding l-(4-amino-5-nitro-6-pyrimidinyl)-2-arylacetylenes 39, which in dry pyridine underwent smooth cyclization to give pyrrolo[2,3-rfJpyrimidine 5-oxides 40 <03SL1151>. 

Amino-6-chloro-5-nitropyrimidine Mercaptopurine 2-Amino-4[Pg.1612]

A soln. of 4-amino-6-chloro-5-nitropyrimidine and NaNg refluxed 8 hrs. in tetrahydrofuran 7-amino[1.2.5]oxadiazolo[3,4-d]pyrimidine 1-oxide. Y 81%. 

Another approach uses the reaction of 6-chloro-5-nitropyrimidines with a-phenyl-substituted amidines followed by base-catalyzed cyclization to pteridine 5-oxides, which can be reduced further by sodium dithionite to the heteroaromatic analogues (equation 97) (79JOC1700). Acylation of 6-amino-5-nitropyrimidines with cyanoacetyl chloride yields 6-(2-cyanoacetamino)-5-nitropyrimidines (276), which can be cyclized by base to 5-hydroxypteridine-6,7-diones (27S) or 6-cyano-7-oxo-7,8-dihydropteridine 5-oxides (277), precursors of pteridine-6,7-diones (278 equation 98) (75CC819). 

Halogenopyrimidines react with active methylene groups, such as those in diethyl malonate, ethyl cyanoacetate, ketene diethylacetal, etc. For example, 4-chloro-6-methyl-5-nitropyrimidin-2-amine (454) and dimethyl sodiomalonate give dimethyl 2-amino-6-methyl-5-nitropyrimidin-4-ylmalonate (455) (63ZOB3132) 2-chloro-4,6-... 

Nair and Baugh have described the synthesis of isoFA (462) (Scheme 3.92) [202]. Arylation of (457) with 2-amino-6-chloro-4-hydroxy-5-nitropyrimidine in refluxing aqueous ethanol gave (458). Reduction of (458) with sodium... 

Propioiactone 2. SOCI2 3, CH2N2, 4- HBr 5. H2NOH 6. PhthNK, l8-crown-6, MeCN 7. H2NNH2, 8. 2-amino-4-chloro-6-hydroxy-5-nitropyrimidine, 9. aq. HCI 10. Na2S204 ... 

Amino-4,6-dihydroxy-5-nitropyrimidine, 1436 2-Carbamoyl-2-nitroacetonitrile, 1116 5 -Chloro-1,3-di methy 1-4-nitro-1 A-pyrazole. 1864 Mercuiy(II) 5-nitrotetrazolide, 0981 1 -Methylamino-1 -methy lthio-2-nitroethene, 1596 Methy Initrothiophene, 1850 Nitroacetaldehyde, 0763 2-Nitroethanol, 0871... 

The nucleophilic substitution of 4-chloro-5-nitropyrimidines by a-aminocarbonyl compounds, followed by cyclization and oxidation, is also a useful, and widely applicable, method for the synthesis of pteridines (in place of the 5-nitro substituent aryldiazenyl or nitroso moieties can also be used). This reaction is sometimes known as the Polonovski-Boon synthesis.130,131 The use of aminoacetaldehyde diethyl acetal gives 6,7-unsubstituted pteridines, whilst amino ketones, aminonitriles, and amino esters give 6-alkyl-, 6-amino-, and 6-oxopteridines, respectively. 

Hexahydrohomofolic acid (V.36) was synthesized by Nair et al. [221] by condensation of 2,4-diamino-6-chloro-5-nitropyrimidine with the amino ketal (V.37), followed by ketal acidolysis, reductive cyclization to a 7,8-dihydropteridine, aerobic oxidation, ester hydrolysis, A, A -bis(tri-fluoroacetylation), mixed anhydride condensation with diethyl L-glutamate, and cleavage of the ester and amide groups with base. Ketal (V.37) was... 

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