Journal of Medicinal Chemistry
ARTICLE
7.73 (m, 1H), 7.64 (d, 1H, J = 3.5 Hz), 7.06 (m, 1H), 4.43 (d, 2H, J = 5.8
Hz), 4.08ꢀ3.95 (m, 4H), 3.82 (s, 3H), 1.23 (t, 6H, J = 7.0 Hz). ESI-MS
m/z 455 (M þ Na)þ.
J = 5.2 Hz), 7.19 (d, 1H, J = 3.2 Hz), 6.96 (d, 1H, J = 5.2 Hz), 5.60ꢀ5.43
(m, 2H), 4.69ꢀ4.12 (m, 3H), 1.22 (s, 9H). ESI-MS m/z 494 (M ꢀ H)ꢀ.
(S)-1-[20-(tert-Butoxycarbonylamino)-20-carboxyethyl]-3-[(2-
carboxythien-3-yl)methyl]thieno[3,2-d]pyrimidin-2,4-dione (21b). Start-
ing from 19b, and following the same procedure used for the synthesis of
12a, the title compound was obtained as a white amorphous solid (yield
38%). 1H NMR (CD3OD) δ 7.98 (d, 1H, J = 5.2 Hz), 7.46 (d, 1H, J = 5.2
Hz), 7.34 (d, 1H, J = 5.2 Hz), 7.01 (d, 1H, J = 5.2 Hz), 5.65ꢀ5.46
(m, 2H), 4.71ꢀ4.65 (m, 2H), 4.16 (m, 1H), 1.22 (s, 9H). ESI-MS m/z 494
(M ꢀ H)ꢀ.
Diethyl 3-[(3-(2-(Methoxycarbonyl)thiophen-3-yl)ureido)methyl]-
thiophen-2-phosphonate (18d). Starting from methyl 2-aminothiphene-
3-carboxylate and 17b, and following the same procedure used for the
synthesis of 18a, the title compound was obtained as a white solid (yield
73%). 1H NMR (DMSO-d6) δ 9.33 (br s, 1H), 8.14 (t, 1H, J = 5.3 Hz),
7.93ꢀ7.90 (m, 2H), 7.77 (d, 1H, J = 5.5 Hz), 7.02 (m, 1H), 4.45 (d, 2H,
J = 5.2 Hz), 4.08ꢀ3.97 (m, 4H), 3.79 (s, 3H), 1.23 (t, 6H, J = 7.0 Hz). ESI-
MS m/z 455 (M þ Na)þ.
(S)-1-[20-(tert-Butoxycarbonylamino)-20-carboxyethyl]-3-[(2-diethy-
lphosphonothien-3-yl)methyl]thieno[3,4-d]pyrimidin-2,4-dione (21c).
Starting from 19c, and following the same procedure described for 12a
(but using only 1.56 mmol of NaH), the title compound was obtained as a
white amorphous solid (yield 38%). 1H NMR (CD3OD) δ 8.34 (d, 1H,
J = 3.2 Hz), 7.71 (m, 1H), 7.19 (d, 1H, J = 3.2 Hz), 7.11 (m, 1H),
5.39ꢀ5.36 (m, 2H), 4.76ꢀ4.50 (m, 2H), 4.25ꢀ4.12 (m, 5H), 1.33 (t, 6H,
J = 7.0 Hz), 1.24 (s, 9H). ESI-MS m/z 586 (M ꢀ H)ꢀ.
3-[(2-Carboxythien-3-yl)methyl]thieno[3,4-d]pyrimidin-2,4-dione
(19a). A mixture of 18a (470 mg, 1.2 mmol) and TFA (4 mL) in DCM
(20 mL) was stirred at rt for 3 h. Then the solvent was evaporated, the
residue was suspended in 15 mL of MeOH, and 4 mL of NaOH 2N were
added. The resulting mixture was refluxed for 1 h. Then MeOH was
evaporated, water (8 mL) was added to the residue, and the solution was
cooled to 0 ꢀC, acidified with HCl 4N, and the formed solid filtered and
dried in oven at 60 ꢀC to give 19a as a white solid (yield 69%). 1H NMR
(DMSO-d6) δ 13.16 (br s, 1H), 11.99 (br s, 1H), 8.09 (d, 1H, J = 4.9
Hz), 7.67 (d, 1H, J = 4.9 Hz), 6.95 (d, 1H, J = 5.2 Hz), 6.74 (d, 1H, J = 5.2
Hz), 5.31 (s, 2H). ESI-MS m/z 307 (M ꢀ H)ꢀ.
(S)-1-[20-(tert-Butoxycarbonylamino)-20-carboxyethyl]-3-[(2-diethylphos-
phonothien-3-yl)methyl]thieno[3,2-d]pyrimidin-2,4-dione (21d). Starting
from 19d, and following the same procedure described for 21c, the title
compound was obtained as a white amorphous solid (yield 45%). 1H NMR
(CD3OD) δ 7.99 (d, 1H, J = 5.2 Hz), 7.72 (m, 1H), 7.34 (d, 1H, J = 5.2
Hz), 7.16 (m, 1H), 5.47ꢀ5.45 (m, 2H), 4.74ꢀ4.44 (m, 2H), 4.24ꢀ4.15
(m, 5H), 1.38(t, 6H, J=7.0Hz), 1.23(s, 9H). ESI-MSm/z586 (Mꢀ H)ꢀ.
(S)-1-(20-Amino-20-carboxyethyl)-3-[(2-carboxythien-3-yl)methyl]-
thieno[3,4-d]pyrimidin-2,4-dione (7a). Starting from 21a, and follow-
ing the same procedure used for the synthesis of 6a, the title compound
was obtained as a white solid (yield 98%); [R]20D = þ29.1ꢀ (c 0.72, HCl
6N). 1H NMR (D2O) δ 8.27 (d, 1H, J = 3.2 Hz), 7.22
(d, 1H, J = 5.2 Hz), 7.01 (d, 1H, J = 3.2 Hz), 6.65 (d, 1H, J = 5.2
Hz), 5.31 (m, 2H), 4.46ꢀ4.26 (m, 2H), 4.04 (m, 1H). 13C NMR (D2O)
δ 171.6, 159.8, 152.7, 139.8, 136.9 (2C), 136.0, 132.6, 128.6, 127.4,
121.1, 104.7, 53.6, 46.7, 41.3. ESI-MSꢀm/z 394 (M ꢀ H)ꢀ. HRMS (ESI)
m/z calculated for C15H12N3O6S2 (M ꢀ H)ꢀ 394.0173, found
394.0175. Anal. (C15H13N3O6S2) C, H, N.
3-[(2-Carboxythien-3-yl)methyl]thieno[3,2-d]pyrimidin-2,4-dione
(19b). To a solution of 18b (782 mg, 1.97 mmol) in THF (20 mL)
cooled to 0 ꢀC, sodium tert-butoxide (480 mg, 4.98 mmol) was added,
and the resulting suspension was stirred for 1 h at rt. Then the solvent
was evaporated, the residue was dissolved in 10 mL of water, and the
solution was cooled to 0 ꢀC and acidified by addition of HCl 4N. The
formed precipitate was filtered, washed with water and MeOH, and dried
1
in oven at 60 ꢀC to give 19b as a white solid (yield 76%). H NMR
(DMSO-d6) δ 13.16 (br s, 1H) 11.34 (br s, 1H), 8.40 (d, 1H, J = 3.2 Hz),
7.44 (d, 1H, J = 5.2 Hz), 6.87 (d, 1H, J = 3.2 Hz), 6.61 (d, 1H, J = 5.2 Hz),
5.31 (m, 2H). ESI-MS m/z 307 (M ꢀ H)ꢀ.
Methyl 4-(6,8-Dioxo-5,6-dihydro-4H-thieno[3,2-e][1,3]diazepin-
7(8H)-yl)thiophen-3-carboxylate (20). The title compound was obtained
as byproduct in the synthesis of 19b. The methanol acidic solution, from
which 19b was precipitated, and the methanol layers used to wash 19b
were collected and concentrated. The residue was purified by means
of flash chromatography (EtOAc/MeOH, 4:1) to give 20 as a white solid
(S)-1-(20-Amino-20-carboxyethyl)-3-[(2-carboxythien-3-yl)methyl]-
thieno[3,2-d]pyrimidin-2,4-dione (7b). Starting from 21b, and follow-
ing the same procedure used for the synthesis of 6a, the title compound
was obtained as a white solid (yield 95%); [R]20D = þ20.5ꢀ (c 0.14, HCl
6N). 1H NMR (D2O) δ 7.55 (d, 1H, J = 5.2 Hz), 7.05 (d, 1H, J = 5.2 Hz),
6.73 (d, 1H, J = 5.2 Hz), 6.30 (d, 1H, J = 5.2 Hz), 4.92ꢀ4.78.(m, 2H),
4.14ꢀ4.02 (m, 3H). 13C NMR (D2O) δ 168.5, 165.1, 159.5, 152.8,
145.6, 144.2, 137.9, 132.6, 127.6, 126.8, 116.5, 113.0, 51.3, 46.0,
41.3. ESI-MS m/z 394 (M ꢀ H)ꢀ. HRMS (ESI) m/z calculated for
C15H12N3O6S2ꢀ (M ꢀ H)ꢀ 394.0173, found 394.0170. Anal. (C15H13-
N3O6S2) C, H, N.
1
(yield 15%). H NMR (DMSO-d6) δ 11.35 (br s, 1H), 8.41 (d, 1H,
J = 2.6 Hz), 7.73 (d, 1H, J = 3.2 Hz), 6.87 (d, 1H, J = 2.6 Hz), 6.79 (d, 1H,
J = 3.2 Hz), 5.28 (s, 2H), 3.83 (s, 3H). ESI-MS m/z 345 (M þ Na)þ.
3-[(2-Diethylphosphonothien-3-yl)methyl]thieno[3,4-d]pyrimidin-
2,4-dione (19c). To a freshly prepared 5N NaOEt solution (20 mL), 18c
(688 mg, 1.59 mmol) was added and the suspension was stirred at rt for
3 h. Then the solvent was evaporated and the residue was taken up with
water (10mL). The solution was cooledto 0 ꢀC and acidified by dropwise
addition of HCl 4N. The obtained precipitate was recovered by filtration
and dried in oven at 60 ꢀC to give 19c as a white solid (yield, 99%).
1H NMR (DMSO-d6) δ 11.33 (br s, 1H), 8.41 (d, 1H, J = 3.2 Hz), 7.83
(m, 1H), 6.88ꢀ6.83 (m, 2H), 5.17 (s, 2H), 4.11ꢀ4.02 (m, 4H), 1.26
(t, 6H, J = 7.0 Hz). ESI-MS m/z 423 (M þ Na)þ.
(S)-1-[20-Amino-20-carboxyethyl]-3-[(2-phosphonothien-3-yl)met-
hyl]thieno[3,4-d]pyrimidin-2,4-dione (7c). To a suspension of 21c
(200 mg, 0.34 mmol) in DCM (15 mL), bromotrimethylsilane (900 μL,
6.8 mmol) was added and the mixture was refluxed for 18 h. Then the
volatiles were evaporated and crude product was purified by means of
Dowex resin as described for 6a to give 7c as a white solid (yield 91%);
[R]20D = þ25.0ꢀ (c 0.2, H2O). 1H NMR (D2O) δ 8.28 (d, 1H, J = 3.2 Hz),
7.29 (m, 2H), 7.01 (d, 1H, J = 3.2 Hz), 5.22ꢀ5.19 (m, 2H), 4.49ꢀ4.26 (m,
2H), 4.04ꢀ4.00 (m, 1H). 13C NMR (D2O) δ 171.6, 159.9, 152.8, 140.2
(JCꢀP = 9.9 Hz), 137.0, 132.9 (JCꢀP = 181.2 Hz), 132.6, 128.9 (JCꢀP =
6.7 Hz), 127.5 (JCꢀP = 14.9 Hz), 121.2, 104.7, 53.7, 46.7, 41.6. 31P NMR
(D2O) δ 4.92. ESI-MS m/z 432 (M þ H)þ, 430 (M ꢀ H)ꢀ. HRMS (ESI)
3-[(2-Diethylphosphonothien-3-yl)methyl]thieno[3,2-d]pyrimidin-
2,4-dione (19d). Starting from 18d and following the same procedure
described for 19c, the title compound was obtained as a white solid
1
(yield 99%). H NMR (DMSO-d6) δ 11.97 (br s, 1H), 8.09 (d, 1H,
J = 5.2 Hz), 7.84 (m, 1H), 6.95 (d, 1H, J = 5.2 Hz), 6.83 (m, 1H), 5.19
(s, 2H), 4.09ꢀ4.02 (m, 4H), 1.25 (t, 6H, J = 7.0 Hz). ESI-MS m/z 423
(M þ Na)þ.
ꢀ
(S)-1-[20-(tert-Butoxycarbonylamino)-20-carboxyethyl]-3-[(2-car-
boxythien-3-yl)methyl]thieno[3,4-d]pyrimidin-2,4-dione (21a). Start-
ing from 19a, and following the same procedure used for the synthesis
of 12a, the title compound was obtained as a white amorphous solid
(yield 19%). 1H NMR (CD3OD) δ 8.34 (d, 1H, J = 3.2 Hz), 7.47 (d, 1H,
m/z calculated for C14H13N3O7PS2 (M ꢀ H)ꢀ 429.9938, found
429.9942. Anal. (C14H14N3O7PS2) C, H, N.
(S)-1-[20-Amino-20-carboxyethyl]-3-[(2-phosphonothien-3-yl)met-
hyl]thieno[3,2-d]pyrimidin-2,4-dione (7d). Starting from 21d, and fol-
lowing the same procedure used for the synthesis of 7c, the title compound
4802
dx.doi.org/10.1021/jm2004078 |J. Med. Chem. 2011, 54, 4793–4805