6-[(Dimethylamino)methylene]amino-1,3-dimethyluracil: A versatile aza-diene substrate for cycloaddition and michael-type reactions

Efficient Synthesis of N-3-Substituted 6-Aminouracil Derivatives via N6-[(Dimethylamino)methylene] Protection

“…Despite its common use as a protecting group in the purine chemistry, 6 to the best of our knowledge a [(dimethylamino)methylene] moiety has not been used with this purpose on 6aminouracil. 7 As starting materials, we chose either 6-amino-1benzyluracil 3,8 (1) or 6-amino-1-methyluracil 3,9 (4) (Scheme 2) which were quantitatively transformed into the corresponding formamidines 2 or 5, respectively, by reaction with DMF-dimethyl acetal (DMF-DMA) in DMF at 40 ºC. This reaction can be easily followed by TLC.…”

The Reactivity of Related 6-Amino- and 5,6-Diaminouracils Derived from 2-Amino-5-(phenoxymethyl)-2-oxazoline: Efficient Access to Bicyclic Pyrimidine Derivatives

“…Such a shielded signal observed at 11.40 ppm for the proton on the N-7 atom of the xanthine skeleton has been already described in the literature data (d = ~11.30 ppm). 9,10 In conclusion, this paper highlights the reactivity of 6aminouracil 6 and 5,6-diaminouracil 3, both derived from 2-amino-2-oxazoline 1, leading to racemic 8-(dimethylamino)-3- Melting points were determined with an SM-LUX-POL Leitz hotstage microscope and are uncorrected. The IR spectra were recorded on a Bruker IFS-25 spectrophotometer; NMR spectra ( 1 H, 13 C, and 1 H COSY) were recorded at 300 MHz or 75 MHz with TMS as an internal standard using a Bruker AVANCE 300 spectrometer.…”

“…As a Michael adduct model, 7 could be considered as a key intermediate in the formation of new 8-(dimethylamino)theophylline derivatives by thermal cyclization reactions. 9,10,12,13 Hence, the target 8-(dimethylamino)xanthine 2 was obtained by heating 7 in nitrobenzene at 190-200 °C (Scheme 3). The structure of 2 was assigned on the basis of elemental and spectral analyses.…”

Synthesis of Fused Pyridine Carboxylates by Reaction of β-Alkoxyvinyl Glyoxylates with Amino Heterocycles

“…hetarylacetonitriles (Scheme 1). For this purpose, 5-aminopyrazoles or -isoxazoles [18][19][20][21][22][23][24][25][26][27][28] and 6-aminouracils [29][30][31][32][33][34][35] were applied as the NCC binucleophiles. In some cases, the regioselective preparation of fused pyridine -or -carboxylates was achieved via catalytic mode 2,6,21,29 or via two-step protocols.…”

“…In some cases, the regioselective preparation of fused pyridine -or -carboxylates was achieved via catalytic mode 2,6,21,29 or via two-step protocols. 24,25,33,35 Acyl pyruvates 10 bearing (het)aryl substituents, as well as the corresponding -arylidene derivatives were used predominantly as the CCC bis-electrophiles;…”