4- Chloro-5-nitropyrimidine, reaction with

Treatment with silver(I) fluoride converts 2,4,5,6-tetrachloropyrimidine, in a smooth reaction at 90°C for 4 hours, into 5-chloro-2,4,6-trifluoropyrimidine in 84% yield, thus replacing the activated chlorines, namely those which are attached to the carbons in the a-positions to the electron-withdrawing nitrogens. All attempts to substitute the chlorine in the 5-position with fluorine failed. 2,4,6-Trichloropyrimidine, upon reaction with silver(I) fluoride at room temperature, gives 2,4,6-trifluoropyrimidine in 82 % yield. All preparations were carried out by refluxing three times with new portions of silver(I) fluoride.32 4,6-Dichloro-5-nitropyrimidine is converted into 4,6-difluoro-5-nitropyrimidine in 75% yield upon treatment with silver(I) fluoride at 170°C for 1 hour.33... 

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>. 

An example of this reaction is the synthesis of 4,6-dimethylpteridin-2-amine (1) from 2,4-dichloro-6-methyl-5-nitropyrimidine and aminoacetone. Initially 4-acetonylamino-2-chloro-6-methyl-5-nitropyrimidine is formed which, by reaction with ammonia, gives the corresponding pyrimidin-2-amine.132 This undergoes reductive cyclization to 4,6-dimethyl-7,8-dihydropteridin-2-amine, which may be subsequently oxidized (potassium permanganate) to l.133... 

Mercaptothiazolo[5,4-d]pyrimidines easily obtained from 6-chloro-5-nitropyrimidines by the reaction with carbon disulfide and sodium sulfide [138]. 

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). 

Activated compounds such as 5-nitropyrimidin-2-one and 1-methyl-5-nitro-2-pyridone form the 2-chloro analogs with thionyl chloride 223b. 312b displacement of the —O—SO—Cl group. In reactions... 

Pagoria and co-workers synthesized a number of thermally stable explosives from the reaction of the sodium salt of ANTA with chloro-substituted arylenes and A-heterocycles. These include the synthesis of (117) from picryl ehloride, PRAN (118) from 2-chloro-3,5-dinitropyridine, IHNX (119) from 2,4-dichloro-5-nitropyrimidine, (120) from 1,5-dichloro-2,4-dinitrobenzene, and (121) from 4-chloro-6-(3-nitro-l,2,4-triazolyl)-5-nitropyrimidine. Coburn and co-workers " reported the synthesis of the tetrazine (122) and the triazine (123) from the reaction of the sodium salt of ANTA with 3,6-dichlorotetrazine and cyanuric chloride respectively. 

Reactions of 4(6)-chloro-5-nitropyrimidines with nucleophilic agents 93KFZ(4)26. 

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