+
+
Substituted Thieno[2,3-d]pyrimidinone Derivatives
J ournal of Medicinal Chemistry, 1997, Vol. 40, No. 4 583
(DMSO-d6) δ 1.84 (m, 6H, CH2CH2CH2, H-6,7), 2.50 (m, 6H,
CH2N, piperazine H), 2.70 (m, 2H, H-5), 2.84 (m, 2H, H-8),
3.13 (m, 6H, piperazine H), 3.26 (t, J ) 7.2 Hz, 2H, SCH2),
3.44 (s, 3H, NCH3), 3.77 (s, 3H, OCH3), 6.86-6.92 (m, 4H,
ArH).
6H, H-8, piperazine H), 3.76 (s, 3H, OCH3), 4.10 (t, J ) 7.5
Hz, 2H, CONCH2), 6.80-6.90 (m, 4H, ArH).
Compound 81: 1H NMR (DMSO-d6) δ 1.83 (m, 4H, H-6,7),
1.96 (m, 2H, CH2CH2CH2), 2.51 (m, 6H, CH2N, piperazine H),
2.55 (s, 3H, SCH3), 2.76 (m, 2H, H-5), 2.87 (m, 2H, H-8), 2.96
(m, 4H, piperazine H), 3.77 (s, 3H, OCH3), 4.54 (t, J ) 6.3 Hz,
2H, OCH2), 6.85-6.90 (m, 4H, ArH).
Hyd r olysis of 2-[[3-[4-(4-Ch lor op h en yl)-1-p ip er a zin yl]-
p r op yl]t h io]-5,6,7,8-t e t r a h yd r o[1]b e n zot h ie n o[2,3-d ]-
p yr im id in -4(1H)-on e (52) (Sch em e 2). To a suspension of
compound 52 (0.7 g, 1.5 mmol) in ethanol (15 mL) was added
hydrochloric acid 6 N (20 mL), and the mixture was refluxed
for 6 h. After cooling, the solid was collected by filtration;
recrystallization from acetic acid gave 0.139 g (42%) of
compound 75 as white crystals: mp 315 °C; IR (KBr) 3160
2-(2-Ch lor oet h yl)-6,7-d im et h yl-8H -[1,3,4]t h ia d ia zolo-
[3,2-a ]th ien o[2,3-d ]p yr im id in -8-on e (82) (Sch em e 4). To
a mixture of potassium salt 23 (0.9 g, 3.4 mmol), P2O5 (0.48 g,
3.4 mmol), and CH3SO3H (2.20 mL, 38 mmol) was added
3-chloropropionyl chloride (0.33 mL, 3.4 mmol), and the
mixture was stirred for 4 h at 80-90 °C. The cooled reaction
mixture was poured into cold water and neutralized with 10%
NaOH. The solid product was filtered and washed with water.
Recrystallization from ethanol/dioxane gave 0.43 g (42%) of
82 as a light brown powder: mp 216-218 °C dec; IR (KBr)
and 3100 (NH), 1700 and 1650 (CdO) cm-1. Anal. (C10H10
-
N2O2S) C, H, N, S.
These analytical and spectral data were like those of known
compound.29 From the filtrate, concentrated and neutralized
with 10% NaOH, was obtained a solid that, twice recrystallized
from ethanol, yielded 10 mg of 76 as a white powder: mp 107-
109 °C; MS m/e 270 (M+). Anal. (C13H19ClN2S) C, H, N, S.
The analytical and spectral data were similar to those of the
compound synthesized with the following procedure.
1-(3-Mer captopr opyl)-4-(4-ch lor oph en yl)piper azin e (76)
(Sch em e 2). A mixture of 1-(3-chloropropyl)-4-(4-chloro-
phenyl)piperazine (35) (0.65 g, 2.4 mmol) and thiourea (0.19
g, 2.5 mmol) was refluxed in ethanol (4 mL) for 4 h. A solution
of sodium hydroxide (1.05 g, 26 mmol) in 80% ethanol (6 mL)
was added, and the reaction mixture was refluxed for another
40 h. To the cooled reaction mixture was added 4 N hydro-
chloric acid (5 mL), and the mixture was heated for 30 min.
The solution, neutralized with 10% NaOH, gave, by recrys-
tallization from ethanol, 50 mg of the desired product 76 as a
white powder: mp 107-109 °C; 1H NMR (DMSO-d6) δ 1.82
(m, 2H, CH2CH2CH2), 2.42 (t, J ) 7 Hz, 2H, CH2N), 2.49 (t, J
) 5.1 Hz, 4H, piperazine H), 2.78 (t, J ) 7 Hz, 2H, CH2SH),
3.10 (t, J ) 5.1 Hz, 4H, piperazine H), 6.86-7.20 (m, 4H, ArH).
Anal. (C13H19ClN2S) C, H, N, S.
1
1680 (CdO) cm-1; H NMR (CDCl3) δ 2.38 (s, 3H, CH3), 2.51
(s, 3H, CH3), 3.47 (t, J ) 6.3 Hz, 2H, CH2), 3.92 (t, J ) 6.3 Hz,
2H, CH2Cl). Anal. (C11H10ClN3OS2) C, H, N, S.
2-[2-[4-(2-Me t h oxyp h e n yl)-1-p ip e r a zin yl]e t h yl]-6,7-
d im et h yl-8H -[1,3,4]t h ia d ia zolo[3,2-a ]t h ien o[2,3-d ]p yr i-
m id in -8-on e (83) (Sch em e 4). A mixture of the thiadiazolo
derivative 82 (0.48 g, 1.6 mmol) and 1-(2-methoxyphenyl)-
piperazine (1.6 g, 8.3 mmol) was heated at 140 °C on an oil
bath for 2 h. After the mixture was cooled, the melted residue
was collected with warm ethanol and recrystallized (Table 2):
IR (KBr) 1660 (CdO) cm-1; 1H NMR (DMSO-d6) δ 2.33 (s, 3H,
CH3), 2.40 (s, 3H, CH3), 2.69 (m, 6H, CH2N, piperazine H),
3.03 (m, 4H, piperazine H), 3.20 (m, 2H, CH2), 3.77 (s, 3H,
OCH3), 6.92 (m, 4H, ArH).
P h a r m a cology. Bin d in g Assa ys. Male CRL:CD(SD)BR-
COBS rats weighing about 150 g were killed by decapitation,
and their brains were rapidly dissected (hippocampus for
5-HT1A; striatum for 5-HT1B, D1 and D2; cortex for 5-HT2A
,
5-HT3 and R1 adrenergic receptors), frozen, and stored at -80
°C until the day of assay. Pig brains were obtained from a
local slaughterhouse, and the cortex (for 5-HT2C) was rapidly
removed and stored at -80 °C until assay.
3-Am in o -2[[3[4(2-m e t h o x y p h e n y l)-1-p ip e r a zin y l]-
p r op yl]th io]-qu in a zolin -4(3H)-on e (78) (Sch em e 3). The
3-amino-2,3-dihydro-2-thioxo-quinazolin-4(1H)-one (77)30 (0.45
g, 2.3 mmol) was refluxed with a solution of potassium
hydroxide (0.32 g, 5.7 mmol) in absolute ethanol (23 mL) for 1
h. The suspension was filtered while hot to obtain the
corresponding potassium salt (0.5 g, 2.1 mmol) that was
condensed rapidly with an equimolar amount of piperazine 36.
The suspension was refluxed under stirring in ethanol (15 mL)
for 6 h; after cooling, the solid was collected and recrystallized
Tissue was homogenized in about 50 volumes of ice-cold 50
mM Tris-HCl buffer (pH 7.4) (or 50 mM Hepes-HCl (pH 7.5)
for 5-HT3 receptors) using an Ultra Turrax TP-1810 (2 × 20
s) and centrifuged at 50000g for 10 min (Beckman model J -21B
refrigerated centrifuge). The pellet was resuspended in the
same volume of fresh buffer, incubated at 37 °C for 10 min,
and centrifuged again at 50000g for 10 min. The pellet was
then washed once by resuspension in fresh buffer and centri-
fuged as before. The pellet was then resuspended in the
appropriate incubation buffer (50 mM Tris-HCl (pH 7.7) for
5-HT2A receptors, with the addition of 10 µM pargyline for the
other receptors containing 4 mM CaCl2 for 5-HT1A receptors,
0.1% ascorbic acid for R1 adrenergic receptors, 4 mM CaCl2
and 0.1% ascorbic acid for 5-HT1B and 5-HT2C receptors; 50
mM Hepes-HCl pH 7.4 containing 10 µM pargyline for 5-HT3
receptors, 50 mM Tris-HCl pH 7.1 containing 10 µM pargyline,
120 mM NaCl, 5 mM Kcl, 2 mM CaCl2, 1 mM MgCl2 and 0.1%
ascorbic acid for D1 and D2 receptors) just before the binding
assay.
(Table 2): IR (KBr) 3300 and 3130 (NH), 1665 (CdO) cm-1
;
1H NMR (DMSO-d6) δ 1.88 (m, 2H, CH2CH2CH2), 2.48 (t, J )
7 Hz, 2H, CH2N), 2.54 (m, 4H, piperazine H), 2.98 (m, 4H,
piperazine H), 3.11 (t, J ) 7 Hz, 2H, SCH2), 3.76 (s, 3H, OCH3),
5.75 (s, 2H, NH2), 6.83-6.91 (m, 4H, ArH), 7.42 (t, J ) 7.7
Hz, 1H, H-7), 7.52 (d, J ) 7.7 Hz, 1H, H-5), 7.77 (t, J ) 7.7
Hz, 1H, H-6), 8.08 (d, J ) 7.7 Hz, 1H, H-8).
P r ep a r a tion of 5,6,7,8-Tetr a h yd r o-2-(m eth ylth io)-3-[3-
[4-(2-m e t h oxyp h e n yl)-1-p ip e r a zin yl]p r op yl][1]b e n zo-
th ien o[2,3-d ]p yr im id in -4(3H)-on e (80) a n d of O-Su bsti-
tu ted Isom er 81 (Sch em e 3). 5,6,7,8-Tetrahydro-2-(meth-
ylthio)[1]benzothieno[2,3-d]pyrimidin-4(1H)-one (79)31 (0.53 g,
2.1 mmol), anhydrous potassium carbonate (0.29 g, 2.1 mmol),
and 1-(3-chloropropyl)-4-(2-methoxyphenyl)piperazine (36) (0.67
g, 2.5 mmol) were heated at reflux in acetonitrile (20 mL) for
6 h. After the mixture was cooled, the solid product was
filtered and recrystallized to give a mixture of compounds 80
and 81. The pure compound 80 crystallized from the filtrate
(Table 2). To a solution of compound 79 (0.9 g, 3.6 mmol) in
DMF (30 mL) was added sodium hydride (0.20 g, 8.7 mmol
60% suspension in a mineral oil). The suspension was stirred
for 30 min, piperazine 36 was added, and the reaction mixture
was refluxed under stirring for 5 h. The suspension was
filtered and the filtrate was concentrated under reduced
pressure to give, by two recrystallizations, the desired com-
pound 81 (Table 2).
Binding assays were done as previously described.32 Briefly,
the following incubation conditions were used. 5-HT1A: [3H]-
8-OH-DPAT (sp act. 157 Ci/mmol, NEN) final concentration 1
nM, 30 min, 25 °C (nonspecific binding: 5-HT 10 µM).
5-HT1B: [3H]-5-HT (sp act. 14.6 Ci/mmol, NEN) final concen-
tration 2 nM, 30 min, 25 °C (nonspecific binding: 5-HT 10 µM).
5-HT2A: [3H]ketanserin (sp act. 60.0 Ci/mmol, Amersham) final
concentration 0.7 nM, 15 min, 37 °C (nonspecific binding:
methysergide 1 mM). 5-HT2C: [3H]mesulergine (sp act. 73.0
Ci/mmol, NEN) final concentration 1 nM, 30 min, 37 °C
(nonspecific binding: mesulergine 10 mM). 5-HT3: [3H]-
BRL43694 (sp act. 84.8 Ci/mmol, NEN) final concentration 1
nM, 30 min, 25 °C (nonspecific binding: GR38032 10 µM). D1:
[3H]SCH23390 (sp act. 71.1 Ci/mmol, NEN) final concentration
0.4 nM, 15 min, 37 °C (nonspecific binding: (-)-cis-flupentixol
10 µM). D2: [3H]spiperone (sp act. 19.0 Ci/mmol, NEN) final
concentration 0.2 nM, 15 min, 37 °C (nonspecific binding: (-)-
sulpiride 100 µM). R1-Adrenergic: [3H]prazosin (sp act. 71.8
Compound 80: IR (KBr) 1675 (CdO) cm-1; 1H NMR (DMSO-
d6) δ 1.83 (m, 6H, CH2CH2CH2, H-6,7), 2.48 (m, 6H, CH2N,
piperazine H), 2.58 (s, 3H, SCH3), 2.69 (m, 2H, H-5), 2.89 (m,