Arch. Pharm. Chem. Life Sci. 2007, 340, 26–31
New Uracil, Xanthine, Pteridine and Derivatives
29
Experimental
6-Amino-1,3-dimethyl-5-(ethoxycarbonylmethylidene)-
aminouracil 2f
Yield: 0.35 g (94%), m. p. 190–1928C (ethanol/H
1
Chemistry
2
O). H-NMR: d
All melting points were determined in open glass capillaries on
an Electrothermal Mel.-Temp II apparatus (Electrothermal) and
[ppm] = 1.22–1.28 (t, 3H, CH
CH ),4.14–4.23 (q, 2H, CH ), 7.49 (s, 2H, C
N=CH). Analysis (C10 ) C, H, N.
3
), 3.12 (s, 3H, N
1
-CH
3
), 3.35 (s, 3H, N
3
-
3
2
6
-NH
2
), 8.88 (s, 1H,
1
are uncorrected. H-NMR was recorded on a JEOL JUM-LA
14 4 4
H N O
4
6
00 MHz spectrometer (JEOL, Tokyo, Japan) using DMSO-d as a
solvent and TMS as an internal standard (Chemical shift in d,
ppm). Elemental analyses were performed at the Microanalytical
laboratory, Faculty of Chemistry, Konstanz University, Germany
and are within l0.4% of the theoretical values unless otherwise
stated. Follow up of the reactions and checking the purity of the
compounds were made by TLC on silica gel-coated aluminium
sheets (type 60 F254, Merck, Germany), spots were visualized by
iodine vapors or by irradiation with UV light (254 nm). Com-
pound 1 was prepared following the reported procedure [10–
6
-Amino-1,3-dimethyl-5-(2-furylidene)aminouracil 2g
1
Yield: 0.35 g (97%), m. p. 203–2058C (ethanol). H-NMR: d[ppm] =
3
.16 (s, 3H, N
1 3 3 3
-CH ), 3.36 (s, 3H, N -CH ), 6.57–6.59 (m, 1H, ArH),
7
.00–7.02 (d, 1H, ArH), 7.22 (s, 2H, C
6
-NH
2
), 7.73–7.74 (d, 1H,
) C, H, N.
ArH), 9.53 (s, 1H, N=CH). Analysis (C11
H
12
N
4
O
3
6
-Amino-5-(4-bromobenzylidene)amino-1,3-
dimethyluracil 2h
Yield: 0.42 g (85%), m. p. 173–1758C (ethanol). H-NMR: d [ppm] =
1
1
3].
3
7
.17 (s, 3H, N
.58 (d, 2H, ArH), 7.84–7.87 (d, 2H, ArH), 9.67 (s, 1H, N=CH). Anal-
) C, H, N.
1 3 3 3 6 2
-CH ), 3.39 (s, 3H, N -CH ), 7.39 (s, 2H, C -NH ), 7.56–
General procedure for preparation of compounds 2a–i
To a solution of 5,6-diamino-1,3-dimethyluracil hydrochloride
4 2
ysis (C13H13BrN O
(
1, 1.45 mmol) in hot water (20 mL), ammonium hydroxide was
6
-Amino-1,3-dimethyl-5-(4-nitrobenzylidene)aminouracil
added to pH 8. After cooling, the aromatic or aliphatic aldehyde
e. g. methyl glyoxal or ethyl glyoxalate hemiacetal (1.45 mmol)
was added with stirring at room temperature for 15 min The
formed product was filtered and crystallized from the proper
solvent.
2i
1
Yield: 0.40 g (91%), m. p. A 3008C (DMF). H-NMR: d [ppm] = 3.18 (s,
3H, N -CH ), 3.42 (s, 3H, N -CH ), 7.58 (s, 2H, C -NH ), 8.14–8.19
1
3
3
3
6
2
(dd, 4H, ArH), 9.79 (s, 1H, N=CH). Analysis (C H N O ) C, H, N.
1
3
13
5
4
6
-Amino-1,3-dimethyl-5-(4-methoxybenzylidene)-
N,N9-Bis-(6-amino-1,3-dimethyl-2,4-dioxo-1,2,3,4-
aminouracil 2a
tetrahydropyrimid-5-yl)ethylidinediamine 3
Yield: 0.38 g (90%), m. p. 197–1998C as reported [13] (ethanol).
To a solution of compound 1 (0.5 g, 2.42 mmol) in hot water
(30 mL), ammonium hydroxide was added to pH 8. After cooling,
glyoxal solution (1.21 mmol) was added with stirring for
20 min; the separated yellow product was filtered, washed with
1
H-NMR: d [ppm] = 3.17 (s, 3H, N
), 6.95–6.98 (d, 2H, ArH), 7.2 (s, 2H, C
.87 (d, 2H, ArH), 9.67 (s, 1H, N=CH). Analysis (C14
1
–-CH
3
), 3.40 (s, 3H, N
3
-CH
), 7.83–
) C, H, N.
3
), 3.80
(s, 3H, OCH
3
6
-NH
2
7
H
16
N
4
O
3
ether and crystallized.
1
Yield: 0.56 g, (64%), m. p.: 273–2758C (DMF/H
ppm] = 3.14 (s, 6H, 2CH ), 3.36 (s, 6H, 2CH
exch.), 9.34 (s, 2H, 2CH). Analysis (C14
2
O). H-NMR: d
6
-Amino-5-(benzylidene)amino-1,3-dimethyluracil 2b
[
3
3
), 7.36 (s, 4H, 26NH
18 8 4
H N O ) C, H, N.
2
,
Yield: 0.36 g (94%), m. p. 221–2238C as reported [13] (ethanol).
1
H-NMR: d [ppm] = 3.10 (s, 3H, N
1
-CH ), 3.42 (s, 3H, N
.34 (m, 3H, ArH), 7.38 (s, 2H, C -NH ), 7.86–7.91 (d, 2H, ArH),
14 4 2
.78 (s, 1H, N=CH). Analysis (C13H N O ) C, H, N.
3
3 3
-CH ), 7.29–
7
9
6
2
General procedure for the preparation of compounds
a–f
4
To a solution of 2a–f (1.2 mmol) in DMF (5 mL), triethyl orthofor-
mate (1.5 mmol) was added and the mixture was heated under
reflux for 10 h. After cooling, the reaction mixture was poured
on to cold water and the formed product was filtered, washed
with cold ethanol (90%), and then crystallized.
6
-Amino-1,3-dimethyl-5-(2-pyrilidene)aminouracil 2c
1
Yield: 0.35 g (92%), m. p. 252–2548C (DMF/H
=
2
O). H-NMR: d [ppm]
), 7.29–7.31 (m, 1H, ArH),
), 7.78–7.83 (m, 1H, ArH), 8.38–8.41 (d, 1H,
3.15 (s, 3H, N
1
-CH
3 3 3
), 3.38 (s, 3H, N -CH
7
.43 (s, 2H, C
6
-NH
2
ArH), 8.56–8.61 (d, 1H, ArH), 9.72 (s, 1H, N=CH). Analysis
) C, H, N.
12 13 5 2
(C H N O
1
,3-Dimethyl-2,4-dioxo-6-(4-methoxyphenyl)-1,2,3,4-
tetrahydropteridine 4a
Yield: 0.11 g (31%), m. p. 219–2208C as reported in [13] (4a was
separated by column chromatography of the obtained mixture
6
-Amino-1,3-dimethyl-5-(4-pyrilidene)aminouracil 2d
1
Yield: 0.37 g (98%), m. p. 263–2658C (ethanol). H-NMR: d [ppm] =
3
7
.15 (s, 3H, N
.55 (s, 2H, C
1
-CH
3
), 3.39 (s, 3H, N
), 7.83–7.85 (d, 2H, ArH), 8.54–8.57 (d, 2H,
), C, H, N.
3
-CH
3
), 7.29–7.31 (m, 1H, ArH),
1
of 4a and 5a on silica gel using toluene:ethyl acetate, 1:1). H-
6
-NH
2
NMR: d [ppm] = 3.38 (s, 3H, N
H, OCH ), 7.09–7.19 (d, 2H, ArH), 8.14-8.19 (d, 2H, ArH), 9.38
s,1H, C -H). Analysis (C15 ) C, H, N.
3 3 3
-CH ), 3.58 (s, 3H, N -CH ), 3.84 (s,
1
13 5 2
ArH), 9.66 (s, 1H, N=CH). Analysis (C12H N O
3
3
(
7
14 4 3
H N O
5
-(Acetylmethylidene)amino-6-amino-1,3-dimethyluracil
1
,3-Dimethyl-2,4-dioxo-6-(phenyl)-1,2,3,4-
2
e
1
Yield: 0.28 g (85%), m. p. 229–2308C (DMF). H-NMR: d [ppm] =
tetrahydropteridine 4b
1
2
.36 (s, 3H, CH
3
) 3.12 (s, 3H, N
1
-CH
3
),3.37 (s, 3H, N
3
-CH
3
), 7.63 (s,
Yield: 0.25 g (80%), m. p. A3008C as reported in [13] (ethanol). H-
2
H, C -NH ), 8.87 (s, 1H, N=CH ). Analysis (C
6
2
9
H
12
N
4
O
3
) C, H, N.
NMR: d [ppm] = 3.34 (s, 3H, N -CH ), 3.57 (s, 3H, N -CH ), 7.47–7.58
1
3
3
3
i
2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
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