´
D. Hockova et al. / Tetrahedron 60 (2004) 4983–4987
4985
Table 2. Inhibition of the cell growth in vitro
3.1.2. 2,4-Diamino-6-(hex-1-yn-1-yl)pyrimidine (1b).
Yield 150 mg (79%) of a white solid, mp 130–133 8C
(ethyl acetate). IR nmax (KBr) 3369, 3319, 3166, 2931,
2871, 2232, 1647, 1587, 1525, 1437, 1420. MS (FAB) m/z:
191 [MHþ] (100). For C10H14N4 (190.2) calculated 63.13%
C, 7.42% H, 29.45% N; found 63.11% C, 7.53% H, 29.14%
N. 1H NMR (DMSO-d6): 7.58 (brs, 2H, NH2); 6.95 (brs, 2H,
Compound
IC50, mmol l21
L1210
HL-60
HeLa S3
CCRF-CEM
2a
3a
2c
3c
q10
q10
10.9
3.6
6.6
9.0
4.2
2.1
q10
q10
10.7
7.6
13.3
6.4
3.8
1.9
0
0
NH2); 5.97 (s, 1H, H-5); 2.47 (t, 2H, J(H-3 ,H-4 )¼7.1 Hz,
H-300); 1.51 and 1.40 (br pent 2H, and br pent, 2H, H-40 and
0
H-5 ); 0.90 (t, 3H, J(H-5 ,H-6 )¼7.36 Hz, H-6 ). 13C NMR:
164.67 (C-4); 158.130 (C-2); 139.15 (C-6); 99.46 (C-5);
97.09 and0 75.07 (C-1 and C-20); 29.62, 21.51 and 18.29
(C-30, C-4 and C-50); 13.54 (C-60).
0
0
observed also for derivatives 1e, 1h, 3d and unstable
trimethylsilyl compounds 2b, 3b. Their activity can be
explained by decomposition under the formation of 2d and
3d. The structure-activity relationship of the series of
compounds shows that the 4-amino pyrimidines 1 were less
active than 4-chloro and 4-alkynyl derivatives 2 and 3. The
active compounds bear mostly unsubstituted ethynyl as the
side chain(s) or ethynyl moiety functionalised by phenyl or
hydroxymethyl group.
3.1.3. 2,4-Diamino-6-[(2-trimethylsilyl)ethynyl]pyrimi-
dine (1c). Yield 125 mg (61%) of yellow foam. IR nmax
(KBr) 3467, 3390, 3318, 3182, 2959, 2166, 1622, 1575,
1550, 1407, 1251, 1183, 991, 848. MS (FAB) m/z: 207
[MHþ] (100). For C9H14N4Si (206) calculated 52.39% C,
6.84% H, 27.16% N; found 52.03% C, 6.83% H, 26.82% N.
1H NMR (DMSO-d6): 6.42 (brs, 2H, NH2); 6.02 (brs, 2H,
NH2); 5.80 (s, 1H, H-5); 0.20 (s, 9H, SiMe3). 13C NMR:
164.47 (C-4); 0163.56 (C-2); 147.76 (C-6); 104.38 and 92.93
(C-10 and C-2 ); 98.08 (C-5); 20.21 (3C, SiMe3).
3. Experimental
Unless otherwise stated, solvents were evaporated at
40 8C/2 kPa, and compounds were dried at 2 kPa over
P2O5. Melting points were determined on a Bu¨chi melting
point apparatus. NMR spectra were measured on an FT
NMR spectrometer Varian UNITY 500 (1H at 500 M and
13C at 125.7 M frequency) in dimethyl sulfoxide-d6. Mass
spectra were measured on a ZAB-EQ (VG Analytical)
spectrometer using FAB (ionization by Xe, accelerating
voltage 8 kV, glycerol matrix). 2,4-Diamino-6-chloro-
pyrimidine, 2-amino-4,6-dichloropyrimidine, ethyne
derivatives and Pd(PPh3)2Cl2 were obtained from Sigma–
Aldrich (Praha, Czech Republic). Dimethylformamide was
3.1.4. 2,4-Diamino-6-(3-hydroxyprop-1-yn-1-yl)pyrimi-
dine (1d). Yield 100 mg (61%) of a white solid, mp 204–
206 8C (methanol). IR nmax (KBr) 3427, 3351, 3127, 2236,
2216, 1668, 1639, 1588, 1550, 1431, 1032. MS (FAB) m/z:
165 [MHþ] (30). For C7H8N4O.1/3H2O (170.2) calculated
49.41% C, 5.13% H, 32.92% N; found 49.64% C, 4.89% H,
32.69% N. 1H NMR (DMSO-d6): 6.40 (brs, 2H, NH2); 5.98
0
(brs, 2H, NH2); 5.78 (s, 1H, H-5); 5.35 (t, 1H, J(OH, H-3 )
¼
0
5.0 Hz, OH); 4.24 (d, 2H, J(OH, H-3 )¼5.0 Hz, H-3 ). 13C
NMR: 164.48 (C-4); 163.56 (C-2); 0 148.33 (C-6); 97.59
(C-5); 88.68 and 83.36 (C-10 and C-2 ); 49.38 (C-30).
0
˚
distilled from P2O5 and stored over molecular sieves (4 A)
in argon atmosphere.
3.1.5. 2,4-Diamino-6-(3-hydroxy-3-phenylprop-1-yn-1-
yl)pyrimidine (1e). Yield 160 mg (66%) of a yellow
amorphous solid. IR nmax (KBr) 3454, 3316, 3124, 2221,
1655, 1622, 1579, 1554, 1440, 1188, 980, 700. MS (FAB)
m/z: 241 [MHþ] (100). For C13H12N4O.2/5H2O (247.5)
calculated 63.10% C, 5.21% H, 22.64% N; found 63.12% C,
3.1. 2,4-Diamino-6-ethynylpyrimidines (1a–1g). General
procedure
Dimethylformamide (5 ml), the corresponding ethyne
derivative (3 mmol) and Et3N (0.15 ml) were added through
septum to an argon purged flask containing 2,6-diamino-6-
iodopyrimidine (240 mg, 1 mmol), CuI (10 mg), PdCl2-
(PPh3)2 (50 mg, 0.07 mmol) and the mixture was stirred
at room temperature overnight. The solvent was evaporated
in vacuo and the residue was chromatographed on a
silica gel column (ethyl acetate–methanol) to give com-
pound 1.
1
5.05% H, 22.25% N. H NMR (DMSO-d6): 7.49 (d, 2H,
arom. H); 7.38 (t, 2H, arom. H); 7.31 (t, 1H, arom. H); 6.42
0
0
(brs, 2H, NH2); 6.21 (d, 1H, J(OH, H-3 )¼6.0 Hz, H-3 ); 6.00
0
(brs, 2H, NH2); 5.81 (s, 1H, H-5); 5.55 (d, 1H, J(OH, H-3 )
¼
5.0 Hz, OH). 13C NMR: 164.48 (C-4); 163.57 (C-2);
148.11 (C-6); 128.48 (2C, arom. C); 127.88 (arom. C);
126.57 (2C, arom. C); 97.77 (C-5); 89.95 and 84.13 (C-10
and C-20).
3.1.1. 2,4-Diamino-6-(phenylethynyl)pyrimidine (1a).
Yield 180 mg (84%) of a yellow solid, mp 200–203 8C,
decomp. IR nmax (KBr) 3468, 3313, 3157, 2214, 1628, 1569,
1541, 1420, 757, 689. MS (FAB) m/z: 211 [MHþ] (100). For
C12H10N4 (210.2) calculated 68.56% C, 4.79% H, 26.65%
N; found 68.23% C, 4.91% H, 26.31% N. 1H NMR (DMSO-
d6): 7.72 (brs, 2H, NH2); 7.62 (d, 2H, arom. H); 7.53
(t, 1H, arom. H); 7.50 (t, 2H, arom. H); 7.15 (brs, 2H, NH2);
6.16 (s, 1H, H-5). 13C NMR: 164.58 (2C, C-2 and C-4);
158.16 (C-6); 132.16 (2C, arom. C); 129.24 (2C, arom. C);
120.11 arom. C); 100.03 (C-5); 93.70 and 82.21 (C-10 and
C-20).
3.1.6. 2,4-Diamino-6-(3-hydroxybut-1-yn-1-yl)pyrimi-
dine (1f). Yield 125 mg (70%) of yellow foam. IR nmax
(KBr) 3401, 3205, 2233, 1622, 1581, 1548, 1418, 1203,
1093, 817. MS (FAB) m/z: 179 [MHþ] (100). HRMS (EI):
found 178.0842, calculated for C8H10N4O: 178.0855. H
NMR (DMSO-d6): 7.02 (brs, 2H, NH2); 6.47 (brs, 2H,
1
0
NH2); 5.88 (s, 1H, H-5); 5.59 (t, 1H, J(OH, H-3 )¼5.0 Hz,
OH); 4.56 (br pent, 1H, J¼6.3 Hz, H-30); 1.35 (d, 3H,
0
J(H-4 ,H-3 )¼6.6 Hz, H-4 ). 13C NMR: 164.52 (C-4); 160.85
(C-2); 143.81 (C-6); 98.65 (C-5); 95.22 and 79.21 (C-10 and
C-20); 56.62 (C-30); 24.27 (C-40).
0
0