Grignard reagents, reactions with pyrimidines

Reaction of amidoximes with dicarbonyl compounds in the presence of Ru3(CO)i2 afforded pyrimidine derivatives" . Reaction of oximes of type RCH=CMeC(=NOH)Me with R NCN also leads to pyrimidines" . a-Halo- and dihaloketoximes and Grignard reagents undergo dimerization to 2,4,6-trisubstituted pyrimidines" " For example. 

Reaction of the 3-substituted l,2,3-triazolo[4,5-d]pyrimidines (183) with one equivalent of a Grignard reagent in THF afforded the dihydro compounds 185 after hydrolysis of the intermediates 184. Aromatization of 185 by oxidation with potassium ferricyanide (79CPB3176) or with 2,3-dichloro-4,5-dicyanobenzoquinone (DDQ) (89CPB1731) gave the 3-substituted 7-alkyltriazolopyrimidines 186. Replacement of the methylsul-... 

Chloro-l-phenyl-l//-pyrazolo[3,4-d]pyrimidine reacts with aromatic aldehydes and sodium hydride to yield aryl 1 -phenyl-1 //-pyrazolo[3,4-reaction reduces time and reaction temperature <90CPB1147>. The JV-oxide (158) reacts with Grignard reagents to yield derivatives (132) <76CPB3120>. 

The reaction of Grignard reagents with 2,4-dimorpholino-7-phenylpyrimido[4,5-r7]pyrimidine (8) leads to 4-substituted 5,7-dimorpholino-2-phenyl-3,4-dihydropyrimido[4,5-photochemical conditions, 2,4-dimorpholino-7-phenylpyrimido[4,5- f]pyrimidine (8) reacts with methanol or acetone to give the corresponding 3,4-dihydro derivative 10.63... 

Phosphorinanones have been utilized as substrates for the preparation of alkenes/ amines,indoles, - and in the synthesis of a series of secondary and tertiary alcohols via reduction,and by reaction with Grignard and Refor-matsky - reagents. Phosphorinanones have also been used as precursors to a series of 1,4-disubstituted phosphor ins. The use of 4-amino-l,2,5,6-tetrahydro-l-phenylphosphorin-3-carbonitrile for the direct formation of phosphorino-[4,3-< ] pyrimidines has been reported. ... 

Most pyrimidine carbonitriles show normal nitrile chemistry reductive reactions to methylamines by metal hydrides, hydrolytic reactions, reduction to aldehydes and formation of ketones with Grignard reagents. However, in highly electron-deficient pyrimidines, competition may arise between addition to an electrophilic substituent and the electrophilic pyrimidine ring. In the 5-cyano derivative (426), specific attack of organometallics is in the 4-position, with formation of the dihydro derivatives (427) instead of a ketone <83ACS(B)6I3>. 

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