under reflux for 3 h. Once cool, nitrogen was bubbled through
the solution to remove any residual phosgene present. The
toluene was removed under reduced pressure and the crude
material was purified by dry flash column chromatography on
silica [ethyl acetate–petroleum ether 40–60 1C (1 : 1) changing
(2H, s, CH
2
), 7.01 (2H, t, J 1.9) and 6.29 (2H, dd, J 4.3, J 2.7);
C
d 181.65 (2 quat), 138.82 (2 quat), 134.96 (2 CH), 124.95
(2 CH), 110.97 (2 CH) and 62.15 (CH ). Purification of this
2
material by flash column chromatography [ethyl acetate–
petroleum ether 40–60 1C (1 : 1) changing to ethyl acetate–
methanol] afforded 1,1-di[2-(carbothiomethoxy)pyrrol-1-yl]-
methane 8 (42 mg, 27%), mp 98–99 1C (found: 294.0483.
0
0
to ethyl acetate] to afford dipyrrolo[1,2-c;2 ,1 -f]pyrimidin-
2
a
1
0-one 3 (71 mg, 29%), mp 160–161 1C (lit., mp 162–164 1C)
(
found: C, 68.5; H, 4.35; N, 16.0%. C10
H
8
N
2
Oꢃ0.1H
7.10 (2H, m), 6.96
167.32 (quat),
29.15 (2 quat), 123.47 (2 CH), 113.72 (2 CH), 111.66 (2 CH)
2
O
C
13
H
14
N
2
O
2
S
2
requires M 294.0490); d
(2H, dd, J 4.1, J 1.9), 7.07 (2H, s), 6.77 (2H, apparent t,
J 2.3), 6.15 (2H, dd, J 4.1, J 2.8) and 4.13 (6H, s); d (63 MHz)
199.44 (2 quat), 132.89 (2 quat), 129.28 (2 CH), 120.56 (2 CH),
109.63 (2 CH), 60.91 (CH ) and 57.24 (2 CH ); m/z 294
(M , 29%), 154 (53), 153 (100), 138 (29) and 94 (35).
H
(360 MHz) 7.22
requires C, 69.05; H, 4.7; N, 16.1%); d
H
(
2H, s), 6.36 (2H, br s) and 6.06 (2H, s); d
C
C
1
+
and 59.13 (CH
2
); m/z 172 (M , 96%), 171 (100) and 144 (27);
2
3
2a
+
data are compatible with literature values. A small amount
of 1-(pyrrol-1-yl)-1-(2-carboxypyrrol-1-yl)methane 6 (22 mg,
0 0
5,6-Dihydro-11H-dipyrrolo[1,2-d;2 ,1 -g][1,4]diazepine 9
8%) was identified from its spectra: dH 7.14 (1H, dd, J 4.0,
J 1.8), 6.91 (1H, dd, J 2.6, J 1.9), 6.87 (2H, t, J 2.2), 6.34 (2H, s,
0
0
A solution of 5,6-dihydrodipyrrolo[1,2-d;2 ,1 -g][1,4]diazepin-
1-one 2 (0.18 g, 0.94 mmol) in chloroform (5 mL) was added
to a stirred suspension of lithium aluminium hydride (83 mg,
.2 mmol, 2.3 equiv.) in dry ether (5 mL). Stirring was
CH ), 6.21 (1H, dd, J 4.0, J 2.7) and 6.17 (2H, t, J 2.1); d
2
C
1
1
1
65.59 (quat), 128.99 (quat), 121.37 (quat), 120.61 (2 CH),
20.55 (quat), 109.78 (CH), 109.49 (2 CH) and 59.85 (CH );
+
2
2
m/z 190 (M , 100%).
continued for 1 h at room temperature, after which more of
the hydride reagent was added until the starting material was
consumed (TLC). The excess of hydride was destroyed by
sequential addition of wet ether, water and dilute hydrochloric
acid (2 M). The separated organic layer was washed with
Reaction of thiophosgene with 1,2-di(pyrrol-1-yl)ethane 4
Solutions of 1,2-di(pyrrol-1-yl)ethane 4 (0.13 g, 0.84 mmol) in
chloroform (10 mL) and thiophosgene (0.07 mL, 0.91 mmol,
1
.08 equiv.) in chloroform (10 mL) were added at the same
water, dried (MgSO ) and the solvent was removed under
4
rate to a volume of chloroform (100 mL) at room temperature
over 15 min. After stirring at room temperature for 60 min,
water was added and the layers were separated. The organic
layer was then washed with water (2 ꢂ 30 mL) and brine
reduced pressure to afford the crude material as a black film. It
was dissolved in chloroform and treated with decolourising
charcoal; filtration followed by removal of the solvent under
reduced pressure afforded 5,6-dihydro-11H-dipyrrolo[1,2-
0
0
(
2 ꢂ 20 mL), dried (K
2
CO
3
) and the solvent was removed
d;2 ,1 -g][1,4]diazepine 9 as a yellow solid (0.11 g, 0.63 mmol,
67%) (found: 172.09930. C11 requires M 172.09950); d
(360 MHz) 6.56 (2H, dd, J 2.7, J 1.8), 6.04 (2H, t, J 3.1), 5.95
(2H, m), 4.29 (4H, s, 2 CH ) and 4.06 (2H, s, CH ); d
under reduced pressure to afford an intermediate (0.21 g) with
the following spectroscopic data: d 7.50 (2H, dd, J 4.5, 1.8),
.73 (2H, dd, J 2.4, 2.0), 6.13 (2H, dd, J 4.5, 2.5) and 4.88 (4H,
H
12
N
2
H
H
6
2
2
C
s); d
C
181.69 (2 quat), 138.83 (2 quat), 138.49 (2 CH), 125.39
(63 MHz) 129.59 (2 quat), 120.83 (2 CH), 107.32 (2 CH), 106.48
+
(
2 CH), 110.05 (2 CH) and 49.73 (2 CH ). Purification of the
2
(2 CH), 47.66 (2 CH ) and 25.80 (CH ); m/z 172 (M , 18), 171
2
2
crude material by dry flash column chromatography on silica
ethyl acetate–petroleum ether 40–60 1C (1 : 3) changing to
ethyl acetate–methanol] afforded 1,2-di[2-(carbothiomethoxy)-
(100), 156 (35), 143 (29), 117 (27), 104 (38), 85 (59) and 65 (40).
0
0
[
Reaction of a solution of pyrrolo[1,2-d;2 ,1 -g][1,4]diazepin-
11-one 2 (0.275 mmol) in MeOH (2 mL) with a solution of
sodium borohydride (8.3 mg, 0.22 mmol, 0.79 equiv.) at room
temperature in MeOH (1 mL) gave, after work-up and
purification by dry flash chromatography on silica
[DCM–hexane (1: 1)], impure 5,6-dihydro-11H-dipyrrolo[1,2-
pyrrol-1-yl]ethane 7 as a brown solid (0.13 g, 89%), mp
+
1
16 2 2 2
22–123 1C (found: M 308.0645. C14H N O S requires
M 308.0648); d
2H, dd, J 2.5, J 1.9), 5.99 (2H, dd, J 4.1, J 2.5), 4.85 (4H, s)
and 4.17 (6H, s); d (63 MHz) 199.45 (2 quat), 132.30 (2 quat),
32.03 (2 CH), 112.00 (2 CH), 108.51 (2 CH), 57.01 (2 CH
H
(360 MHz) 7.18 (2H, dd, J 4.1, J 1.9), 6.40
(
0
0
C
d;2 ,1 -g][1,4]diazepine 9 (14.7 mg, o37%). The product is
unstable on silica.
1
3
)
+
2
and 50.34 (2 CH ); m/z 308 (M , 100%), 275 (27) and
0
0
1
54 (32).
5,6-Dihydro-11H-dipyrrolo[1,2-d;2 ,1 -g][1,4]diazepine-3,8-
dicarbaldehyde 10
Reaction of thiophosgene with 1,1-di(pyrrol-1-yl)methane 5
DMF (0.06 mL, 0.78 mmol, 2.10 equiv.) was added to
1,2-dichloroethane (3 mL) and the solution was cooled to
0 1C. After 5 min, phosphoryl chloride (0.07 mL, 0.75 mmol,
2.0 equiv.) was added, followed 5 min later by a solution of
Solutions of 1,1-di(pyrrol-1-yl)methane 5 (0.14 g, 0.96 mmol)
in chloroform (10 mL) and thiophosgene (0.08 mL,
1
.04 mmol, 1.08 equiv.) in chloroform (10 mL) were added
0
0
at the same rate to a volume of chloroform (100 mL) at room
temperature over 15 min. After stirring at room temperature
for 60 min, water was added and the layers were separated.
5,6-dihydro-11H-dipyrrolo[1,2-d;2 ,1 -g][1,4]diazepine 9 (63.5 mg,
0.37 mmol) in 1,2-dichloroethane (2 mL) The mixture was
stirred at room temperature for 19 h, then washed with water
(20 mL), dilute sodium hydroxide solution (2 M, 10 mL) and
brine (10 mL), and the organic fraction was dried (MgSO4).
The solvent was removed under reduced pressure to yield a
dark brown film (0.1641 g) which was purified by dry flash
The organic layer was then washed with H
2
O (2 ꢂ 30 mL) and
brine (2 ꢂ 30 mL), dried (K CO ) and the solvent was
2
3
removed under reduced pressure. The residue (0.58 g)
had the following characteristics: dH 7.54–7.50 (2H, m), 7.05
1
706 | New J. Chem., 2009, 33, 1703–1708
This journal is ꢀc The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2009