Pyrimidine Mannich reaction

Pyrrolo[2,3-d]pyrimidine, 5-cyano-bromination, 4, 506 Pyrrolo[2,3-d]pyrimidine, 5-nitroso-nucleophilic reactions, 4, 507 Pyrrolo[l, 2- c]pyrimidine-3-carboxylic acids methyl ester synthesis, 4, 293 Pyrrolopyrimidine-2,4-diones Mannich reaction, 4, 504 Vilsmeier reaction, 4, 505 Pyrrolopyrimidines synthesis, 4, 514, 517, 524, 527 Pyrrolopyrimidines, chloro-nucleophilic attack, S, 312 Pyrrolo[2,3-d]pyrimidines NMR, 4, 500... 

The Mannich reaction of 2-oxo- (146) and 2-thioxotetrahydro-pyrimidines yields the hexahydropyrido[4,3-d]pyrimidin-2(l//)-one (147) and the corresponding thione. 

Reaction of 2-amino-4/f-pyrido[l,2-n]pyrimidin-4-ones 143 with HNMei -HCl and paraformaldehyde in Dowtherm A afforded a mixture of 3-(A,A-dimethylamino)methyl derivatives 144 and bis-compounds 145 (93FES1225). Mannich reaction of 9-hydroxy-2-methyl-4//-pyri-dor],2-nlpyrimidin-4-one (146) yielded 8-aminomethyl derivatives 147 (94KFZ(10)23). 

Macrocycles 260 Mannich Reaction 19 MCR, pyrimidines/pyrazoles/isoxazoles 46... 

Nitration of 2-substituted 4/7-pyrido[l,2- ]pyrimidin-4-ones with 99% HN03 in cone. H2S04 gave 3-nitro derivatives <2000BMC751, 2001H(55)535>. Mannich reaction of 2-hydroxy-4//-pyrido[l,2-tf]pyrimidin-4-one afforded... 

Alkylation at position 5 of a pyrrolo[2,3-rf pyrimidine occurs via a Mannich reaction. The nucleoside 10 is transformed into the morpholinomethyl derivative 11 in modest yield (Equation 4) <199781067>. 

A rather unusual, and quite specific, Mannich reaction occurs when the pyrrolo[3,2- pyrimidine 14 undergoes reaction with (3i, 4i )-3-hydroxy-4-(hydroxymethyl)pyrrolidine IS and formaldehyde to produce the pseudonucleoside 16 (Scheme 2) <2003OL3639>. 

Mannich reactions and diazo coupling proceed readily in pyrimidines provided activating groups are present in each of the 2-, 4- and 6-positions. 

Direct (IV-substituted)-aminomethylation at the 5-position of pyrimidines with at least two electron-releasing groups can be done by the Mannich reaction a methyl or an amino substituent may also (or preferentially) undergo the reaction, especially if the... 

In the reaction of 3,5-dimethyl-2,6-diphenylpiperid-4-one oxime (10) with acetylene and RbOH-DMSO, migration of the 3a-Me group to the anionic nitrogen atom occurred, leading to 5,7-dimethyl-4,6-diphenyl-4,5,6,7-tetrahydropyrrolo[3,2-c]pyridine (11) (04CHE326). The formation of the N-anion caused aromatization of the tetrahydropyridine ring. Tetrahydropyrrolo[l,2-c]pyrimidine 12 resulted from the decomposition of the intermediate 3H-pyrrole in a retro-Mannich reaction (Scheme 3). 

The typical ring positions available for the introduction of carbofunctional groups by exchange of hydrogen are the various -CONH— functions of pyrido[2,3-t/]pyrimidinones.87 265 322 324 For alkylation or acylation reactions of pyrido[2,3-cf]pyrimidine-2,4(l//,3//)-diones 4, in most cases the NH groups are converted into the respective anions by sodium hydride78 322 or sodium ethoxide.323 Mannich reactions with formaldehyde/piperazines have been reported,323 as has been the introduction of propynyl groups under Mitsunobu conditions.324... 

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