Thermolysis of N,N″-1,ω-alkanediyl-bis[N′- organylthiourea] derivatives

Article abstract of DOI:10.1002/jhet.5570430311

The course of microwave assisted or conventional thermal intramolecular heterocyclization of the title compounds has been found to be dependent on the length of the alkanediyl chain. While 1,3-propanediyl-bisthioureas 5a-c gave both 2-thioxoperhydropyrimidine-1-carbothioamides 8a-c and 8-amino-3,4,5,6- tetrahydro-1,3,7-thiadiazocine-2-thiones 10a-C, thermolysis of 1,4-butanediyl-bisthioureas 6a-c and 1,6-hexanediyl-bisthioureas 7a-c under the same conditions gave solely 9-amino-4,5,6,7-tetrahydro-1,3,8-thiadiazonine-2- thiones 11a-c and 11-amino-1-thia-3,10-diazacycloundec-10-ene-2-thiones 12a-c, respectively. Symmetric N,N′-diorganylthioureas 4a-c were formed in all cases as minor byproducts.

Full text of DOI:10.1002/jhet.5570430311

May-Jun 2006
593
Thermolysis of N,N''-1,ꢀ-Alkanediyl-bis[N'-organylthiourea]
Derivatives
Alaa A. Hassana* and Dietrich Döppb
aChemistry Department, Faculty of Science, El-Minia University, El-Minia, A. R. Egypt
E-mail: alaahassan2001@yahoo.com
bOrganische Chemie, Universität Duisburg-Essen, D-47048 Duisburg, Germany
Received July 20, 2005
S
S
NH
HN
C
N'HR
N'HR
HN
(CH2)n
Δ or MW
+
S
S
(H2C)n
N
N
''
H N
C
S
NHR
S
NHR
n = 3, 4, 6
The course of microwave assisted or conventional thermal intramolecular heterocyclization of the title
compounds has been found to be dependent on the length of the alkanediyl chain. While 1,3-propanediyl-
bisthioureas 5a-c gave both 2-thioxoperhydropyrimidine-1-carbothioamides 8a-c and 8-amino-3,4,5,6-
tetrahydro-1,3,7-thiadiazocine-2-thiones 10a-c, thermolysis of 1,4-butanediyl-bisthioureas 6a-c and 1,6-
hexanediyl-bisthioureas 7a-c under the same conditions gave solely 9-amino-4,5,6,7-tetrahydro-1,3,8-
thiadiazonine-2-thiones 11a-c and 11-amino-1-thia-3,10-diazacycloundec-10-ene-2-thiones 12a-c,
respectively. Symmetric N,N'-diorganylthioureas 4a-c were formed in all cases as minor byproducts.
J. Heterocyclic Chem., 43, 593 (2006).
neat powdered compounds 5, 6, and 7 were either heated
to melt in an oil bath (method A) or subjected to
irradiation in a microwave (MW) oven (method B, see
Table 1 for details) a sticky residue was always
obtained. Chromatographic separation gave numerous
zones, and from the most intense of which the symmetric
thioureas 4a-c and the cyclisation products 8a-c and
10a-c (from 5a-c) or 11a-c (from 6a-c) and 12a-c (from
7a-c) could be isolated (see Table 1 and Scheme 2).
While 4a-c are known compounds, the structures of all
new cyclic products were assigned on the basis of their ir-
and nmr-spectral data. For all new compounds the gross
compositions were derived from satisfactory elemental
analyses, and the molecular masses were extracted in all
cases from the EI-mass spectra, the common features of
which will also be briefly discussed further below.
Introduction.
When either conventionally heated or activated in a
microwave oven in absence of any solvents, the thioureido-
ethylthioureas 1a-c underwent a cyclocondensation with loss
of one molecule of amine yielding the 2-thioxoimidazoline-1-
carbothioic amides 2a-c, the 7-organylimino-1,3,7-thia-
diazepane-2-thiones 3a-c and the symmetric thioureas 4a-c
[1] (Scheme 1). This unique reactivity warrants a more
detailed investigation. Therefore we undertook to prepare a
series of three higher homologues of 1, namely the substituted
thioureidopropyl-, butyl- and hexylthioureas 5a-c, 6a-c and
7a-c, respectively, and to investigate their thermolysis
reactions under the abovementioned conditions.
Results and Discussion.
Compounds 5a [2], 5b [3], 6a [4], 7a [5] and 7c [6]
were known from the literature and were prepared
according to published procedures, and samples 5c, 6b,c
and 7b were prepared analogously. When samples of
The salient features of the nmr-spectra (including 13C
DEPT 135/90 spectra) of products 8 and 10-12 are the
1
following: Unlike in the published [4] H and 13C spectra
of the starting materials 5a and 6a as well as of the newly
prepared compounds 5c, 6b,c and 7b there are no pairs of
truly isochronous CH2-groups, thus symmetric structures
of type 9 are ruled out. Whereas compounds 8a,b show
two different thioxo carbon signals around 175.6 for the
carbothioamide function and around 180.2 for the ring
thione function, compounds 10a,b, 11a-c and 12a-c show
only one thioxocarbon signal between 182.1 and 184.6
ppm, but in addition a signal each from 151.2 to 151.9
ppm, a range close to the chemical shift (157.15) of the
functional C atom of N-phenylisothiourea [7]. These
Scheme 1
S
H
N
S
H
H
N
N
C
NHR
NHR
S
Δ or MW
H
N
H
N R
(H2C)2
S
+
S
+
R
C
N
N
H
C
S
N
H
NR
4a-c
S
NHR
1a-c
3a-c
2a-c
1-4 R
a
b
c
Ph
Bn
Allyl

594
A. A. Hassan and D. Döpp
Vol 43
All products 8 and 10-12 are also characterized in
their ir-spectra by sharp bands at 1541-1574 due to
(NH-deformation and C-N stretching) and intense band
in the range of 1348 – 1373 and 972-1030 cm-1
assigned to strongly coupled between C=S and C-N
vibrations [9-11]. The EI-mass spectra need a brief
comment (see Scheme 3). For 8a-c m/z = 116
represents the 2-thioxoperhydropyrimidinyl fragment
(II, n = 3) formed by release of the corresponding
isothiocyanate from the molecular ion. Since fragment
ions with the masses of these isothiocyanates are also
found it is concluded that the positive charge may
remain alternatively either with the ring or the
isothiocyanate fragment. For 10, 11 and 12 the same
fragmentation process is observed, although a N-carba-
moyl function as in 8 is definitely absent in products
10-12. Since it has been demonstrated that compounds
3 could thermally be converted into the more stable
isomers 2 [1] it seems most logical to assume that in
the mass spectrometer compounds 10-12 are also
transformed into their isomeric radical cations I prior
to fragmentation yielding ions II. Since the nine-
membered ring compounds 11a-c are fragmented
alternatively also by loss of mass 76 (which is assigned
to represent carbon disulfide), another mode of ring
contraction seems to be significant for these three
products, namely loss of CS2 to generate ions III
(Scheme 3).
Scheme 2
S
S
NH
H N
C
N'HR
N'HR
H
N
H
Δ or MW
(H2C)n
R
C
N R
+
S
N
4a-c
''
H N
C
S
S
NHR
8a-c
n = 3: 5a-c
n = 4: 6a-c
n = 6: 7a-c
S
S
Δ or MW
HN
HN
(H2C)n
HN
(CH2)n
S
S
+
S
HN
(H2C)n
HN
N
N
S
R
NHR
NR
A
B
n = 3: 10a-c
n = 4: 11a-c
n = 6: 12a-c
9
4-8, 10-12: a R = Ph; b R = Bn; c R = allyl
signals are therefore assigned to carbon atoms 8 (in 10a-
c), 9 (in 11a-c) and 11 (in 12a-c), respectively. These data
would also fit the tautomeric structures B, but structures
A of 10, 11, and 12 are preferred, since endocyclic double
bonds lead to relief of eclipsing strain in medium sized
rings [8]. All cyclic products show two NH proton signals
each. Whereas the range of chemical shifts for the ring
NH is relatively narrow (7.46 to 7.54 for 8a-c, 7.31 – 7.80
for 10-12), the ꢀ-values for the carbothioamide (in 8a-c)
or exocyclic NHR groups (in 10-12) are dependent on the
nature of R (around 9.5 for R = Ph, 7.8 for R = Bn and 7.4
– 7.5 for R = allyl).
Scheme 3
Table 1
S
H
N
H
N
HN
(H2C)n
Thermolysis of 1.5 g each of pulverized neat starting materials by
conventional heating (A) and MW irradiation (B).
Δ, - e-
(H2C)n
S
S
(H2C)n
S
S
N
N
H
n = 3,4,6
- RNCS
N
Starting
NHR
m/z
R
NHR
II
materials
(mmol)
Reaction conditions
Yields of products in mg (%)
Ph
Bn
Allyl
135
149
99
n = 3: 10a-c
n = 4: 11a-c
n = 6: 12a-c
Method A
Method B
n
m/z
3 116
130
I
5a
(4.36)
A: 145-147 °C.
B: Full power, 6 min.
4a
8a
10a
4b
8b
10b
4c
8c
10c
4a
11a
4b
11b
4c
11c
4a
12a
4b
12b
4c
12c
63 (7)
103 (9)
620 (57)
60 (6)
122 (12)
560 (52)
44 (5)
140 (12)
540 (46)
124 (13)
618 (56)
132 (13)
548 (51)
112 (14)
618 (51)
93 (11)
685 (60)
78 (8)
87 (9)
4
Δ, - e-
154 (14)
685 (63)
111 (11)
184 (17)
602 (56)
61 (7)
196 (17)
604 (51)
162 (17)
754 (68)
178 (18)
652 (60)
144 (18)
732 (61)
128 (14)
796 (70)
111 (12)
661 (59)
126 (17)
770 (52)
n = 3
6
158
8a-c
5b
(4.03)
A: 123-124 °C.
B: Full power, 6 min.
H
N
R
m/z
Δ, - e-
(H2C)4
NR
11a-c
5c
(5.51)
A: 146-148 °C.
B: Full power, 6 min.
Ph 189
Bn 203
153
- CS2
N
H
Allyl
III
6a
(4.19)
6b
(3.88)
6c
(5.24)
7a
(3.88)
7b
A: 184-186 °C.
B: Full power, 8 min.
A: 184-186 °C.
B: Full power, 8 min.
A: 80-82 °C.
B: Power 70%, 4 min.
A: 158-159 °C.
B: Full power, 7 min
A: 164-166 °C.
B: Full power, 7 min.
A: 113-115 °C.
The formation of products 4, 8 and 10-12, respectively,
from 5, 6 and 7, respectively, may be rationalized as
follows (Schemes 4 and 5): Thioureas may thermally be
fragmented to isothiocyanates and amines [12-14], and in
some cases a plethora of additional fragmentation
products has been reported [15,16]. Thus under both
conditions employed in this study (A and B, see Table 1)
bisthioureas 5-7 may release either the isothiocyanates
(3.62)
7c
(4.78)
528 (47)
92 (12)
611 (41)
B: Power 70%, 6 min.

May-Jun 2006
Thermolysis of N,N''-1,ꢀ-Alkanediyl-bis[N'-organylthiourea] Derivatives)
595
R-NCS to generate fragments 13 or one molecule of
amine R-NH2 to generate the thioureidoisothiocyanates
14. Fragments 14 being more reactive than their
precursors 5-7, have three options for further reaction by
intramolecular attack of nucleophilic centers on the
isothiocyanate carbon atom: (i) attack of the thioureido N
generating 8a-c (path a, valid for n = 3), (ii) attack by the
thione sulfur atom with formation of the medium ring
compounds 10-12 (path b, valid for n = 3, 4, 6), and
finally (iii) attack of the thioureido N' (path c). The latter
option is not used since products 9 have not been found.
Path a is also tantamount to direct displacement of N' of
one thioureido group in 5-7 by the central N of the other,
but the process involving intermediate 14 is preferred
here due to the tendency of thioureas to form guanidines
when reacted with amines [17-19]. It is not clear at
present whether this type of reaction, here with 5-7 and
the amine R-NH2 liberated, may affect the yields of 8 and
10-12 by partially consuming the available starting
material 5, 6 or 7.
Scheme 5
S
H2O
H
N
RNCS
R
(R-NH-CHS)2OH2
- COS
RNCS
R
C
OH
H
N
R NH
C
S
4a-c
4a: R = Ph; 4b: R = Bn; 4c: R = Allyl
partly saturated normal or medium sized diaza- or
diazathia-heterocycles owing to the typical and versatile
reactivity of the isothiocyanato and thioureido groups.
Yields may be moderately enhanced by microwave
application instead of conventional thermal activation.
EXPERIMENTAL
The uncorrected melting points were determined with a
Reichart thermover hot stage microscope. The ir spectra were
recorded from KBr disks on Shimadzu 408 or Bruker Vector 22
FT-IR instruments. H (300.13 MHz) and 13C (75.47 MHz) nmr
1
Last, the symmetric thioureas 4a-c may be formed from
the isocyanates R-NCS liberated by either addition of R-
NH2 or by absorbing moisture to generate the thiocar-
bamic acid, which may react with a second molecule of
isothiocyanate to a thiocarbamic anhydride which in turn
spectra (DMSO-d6 as solvent, TMS as internal standard) were
recorded on a Bruker WM300 instrument. Assignment of carbon
resonances has been supported by DEPT experiments. The mass
spectra were recorded on a double focusing AMD 604
spectrometer in the EI Mode at 70 eV ionization energy.
Elemental analyses were determined at the Microanalytical
Centre, Cairo University, Egypt and Carlo Erba Model 1106
Elemental Analyzer (Universität Duisburg- Essen). A Samsung
MX 45 microwave oven was used at its full power 1400 W, 100
% and 70 % power level for the experiments recorded for this
study. Preparative layer chromatography (PLC): Glass plates (48
cm x 20 cm) were coated with silica gel Merck PF254 (applied as
an aqueous slurry and air-dried affording a 1mm layer). Zones
were detected by indicator fluorescence quenching upon 254 nm
illumination, removed from the plates and extracted with
acetone or tetrahydrofuran.
Scheme 4
NH2
(CH2)3,4,6
- RNCS
HN
C
S
NHR
13
5a-c
6a-c
7a-c
a
8a-c
9
n = 3
c
General Procedure for Preparation of Starting Materials.
N
C
a
S
c
To a stirred solution of the diamine (1,3-diaminopropane, 1,4-
diaminobutane or 1,6-diaminohexane) (10 mmol) in 30 ml of
dimethylformamide, phenyl-, benzyl-, or allyl isothiocyanate (20
mmol) was added dropwise at room temperature. Stirring at
room temperature was continued for 3 h, the mixture was set
aside overnight and then added to ice/water. A colourless
precipitate was formed which was recrystallized from a suitable
solvent.
10a-c
11a-c
12a-c
b
b
(H2C)n
HN
S
- RNH2
n = 3,4,6
C
NHR
14
is degraded to COS and 4 analogous to the so-called "self-
condensation" of isothiocyanates described earlier [20].
Amino group exchange reactions between thioureas and
isothiocyanates [21] and between thioureas and primary
amines [22], probably involving an isothiocyanate inter-
mediate, have been reported in the early literature and in
our previous paper [1].
N,N''-1,3-Propanediylbis[N'-phenylthiourea] (5a).
This compound was obtained as colourless crystals (ethanol),
mp 133-135° (Lit. [2] 135-137°), yield (92%); ir: NH 3310,
3195, (NH def. and C-N str.) 1555, (C=S, C-N) 1354, 955 cm-1;
1H nmr ꢀ = 1.78 (m, 2H, CH2), 3.12 (m, 4H, CH2), 7.11-7.41 (m,
10H, phenyl H), 7.62 (br, 2H, NH), 9.42 ppm (br, 2H, NHPh).
Conclusion.
N,N''-1,3-Propanediylbis[N'-(phenylmethyl)thiourea] (5b).
Thermolysis of the easily accessible neat title
compounds allows the solvent-free preparation of fully or
This compound was obtained as colourless crystals (ethanol),
mp 113-115° (Lit. [3] 113-114°), yield (84%); ir: NH 3324,

596
A. A. Hassan and D. Döpp
Vol 43
3216, (NH def. and C-N str.) 1563, (C=S, C-N) 1360, 972 cm-1;
1H nmr: ꢀ = 1.75 (m, 2H, CH2), 3.26 (m, 4H, CH2), 4.65 (br, 2H,
CH2Ph), 7.20-7.46 (m, 10H, phenyl H), 7.55 (br, 2H, NH), 7.90
ppm (br, 2H, NHCH2Ph).
Anal. Calcd. for C22H30N4S2 (414.63): C, 63.73; H, 7.29; N,
13.51; S, 15.47. Found C, 63.61; H, 7.42; N, 13.67; S, 15.31 %.
N,N''-1,4-Hexanediylbis[N'-(2-propenyl)thiourea] (7c).
This compound was obtained as colourless crystals (ethanol),
mp 103-105° (Lit. [6] 100-102°), yield (78%); ir: NH 3288, (NH
N,N''-1,3-Propanediylbis[N'-(2-propenyl)thiourea] (5c).
1
This compound was obtained as colourless crystals (ethanol),
mp 136-138°, yield (76%); ir: NH 3240, 3170, (NH def. and C-
def. and C-N str.) 3194, 1567, (C=S, C-N) 1361,990 cm-1; H
nmr: 1.32 (m, 4H, CH2), 1.53 (m, 4H, CH2), 3.32-3.40 (m, 4H,
CH2), 4.10 (br, 4H, allyl 1-H2), 5.05-5.20 (m, 4H, allyl 3-H2),
5.82-6.00 (m, 2H, allyl 2-H), 7.50 ppm (br, 4H, NH).
1
N str.) 1558, (C=S, C-N) 1361, 966 cm-1; H nmr: ꢀ = 1.70 (m,
2H, CH2), 3.08 (m, 4H, CH2), 4.05 (br, 4H, allyl 1-H2), 5.08-
5.12 (m, 4H, allyl 3-H2), 5.71-5.89 (m, 2H, allyl 2-H), 7.42 (br,
4H, NH) ppm; ms: m/z 272 (M+, 18), 215 (21), 173 (11), 99
(91), 56 (100), 41 (53).
Anal. Calcd. for C11H20N4S2 (272.44): C, 48.50; H, 7.40; N,
20.57; S, 23.54. Found C, 48.34; H, 7.52; N, 20.66; S, 23.41 %.
Heterocyclization of Neat 5a-c, 6a-c and 7a-c.
Method A: By Conventional Heating.
Samples of (1.5 g) were heated in an oil bath to 10 °C above
their melting point. After cooling, tetrahydrofuran (30 ml) was
added and the mixture was subjected to PLC using cyclohexane/
ethyl acetate (1:1) as developing solvent to give numerous
zones. From the thermolyses of 5a-c three intense zones were
extracted with acetone. The fastest migrating zone contained the
disubstituted thiourea 4a-c, the second zone contained the 2-
thioxotetrahydropyrimidine-1-carbothioic acid amide 8a-c and
the slowest zone contained the amino-3,4,5,6-tetrahydro-
[1,3,7]thiadiazocine-2-thiones 10a-c. On the other hand,
chromatographic separation of the residue from the thermolysis
of 10a-c, 11a-c or 12a-c using CHCl3/MeOH (20:1) as eluent
afforded two main zones (extracted with THF). The faster
migrating one contained the disubstituted thiourea 4a-c and the
second zone the amino-4,5,6,7-tetrahydro-3H-[1,3,8]thia-
diazonine-2-thiones 11a-c or the amino-1-thia-3,10-diazacyclo-
undec-10-ene-2-thiones 12a-c.
N,N''-1,4-Butanediylbis[N'-phenylthiourea] (6a).
This compound was obtained as colourless crystals (ethanol),
mp 173-175° (Lit. [4] 174-176°), yield (89%); ir: NH 3288, (NH
def. and C-N str.) 3176, 1560, (C=S, C-N) 1358, 978 cm-1; H
nmr: 1.52 (m, 4H, CH2), 3.32-3.44 (m, 4H, CH2), 7.24-7.47 (m,
10H, phenyl H), 7.60 (br, 2H, NH), 9.40 ppm (br, 2H, NHPh).
1
N,N''-1,4-Butanediylbis[N'-(phenylmethyl)thiourea] (6b).
This compound was obtained as colourless crystals (dioxane),
yield (81%), mp 174-176°, ir: NH 3358, 3212, (NH def. and C-
1
N str.) 1558, (C=S, C-N) 1373, 963 cm-1; H nmr: 1.48 (m, 4H,
CH2), 3.36 -3.43 (m, 4H, CH2), 4.64 (br, 4H, CH2Ph), 7.23-7.35
(m, 10H, phenyl H), 7.49 (br, s, 2H, NH), 7.82 ppm (br, s, 2H,
NH); ms: m/z 386 (M+, 10), 279 (18), 237 (8), 149 (88), 106
(63), 91 (100), 65 (33), 41 (48).
Anal. Calcd. for C20H26N4S2 (386.58): C, 62.14; H, 6.78; N,
14.49; S, 16.59. Found C, 62.28; H, 6.62; N, 14.57; S, 16.44 %.
Method B: By Microwave Irradiation.
Samples of 1.5 g of powdered starting materials were MW-
irradiated to melting in an open glass tube (for the time listed in
Table 1). After completion of the reaction as monitored by TLC,
the residue was separated as reported above. Comparison of the
yields from both methods is given in Table 1.
N,N''-1,4-Butanediylbis[N'-(2-propenyl)thiourea] (6c).
This compound was obtained as colourless crystals (ethanol),
yield (77%), mp 70-72°; ir: NH 3237, (NH def. and C-N str.)
1
1567, 1361, (C=S, C-N) 993 cm-1; H nmr: 1.47 (m, 4H, CH2),
3.39-3.46 (m, 4H, CH2), 4.02 (br, 4H, allyl 1-H2), 5.05-5.16 (m,
4H, allyl 3-H2), 5.77-5.90 (m, 2H, allyl 2-H), 7.45 ppm (br, 4H,
NH); ms: m/z: 286 (M+, 12), 229 (9), 187 (13), 174 (11), 99
(79), 56 (90), 41 (100).
1,3-Diphenylthi ourea (4a).
This compound had mp: 151-153° (Lit. [23] 152-153° [24],
151-152 o).
Anal. Calcd. for C12H22N4S2 (286.46): C, 50.31; H, 7.74; N,
19.56; S, 22.39. Found C, 50.48; H, 7.85; N, 19.39; S, 22.53 %.
1,3-Dibenzylthiourea (4b).
This compound had mp: 146-148° (Lit. [23] 145-147° [24],
146-147o).
N,N''-1,6-Hexanediylbis[N'-phenylthiourea] (7a).
This compound was obtained as colourless crystals (ethanol),
mp 148-150° (Lit. [5] 148-149°), yield (94%); ir: NH 3344,
3222, NH def. and C-N str.) 1560, (C=S, C-N) 1366, 976cm-1;
1H nmr: 1.24 (m, 4H, CH2), 1.46 (m, 4H, CH2), 3.38-3.41 (m,
4H, CH2), 7.16-7.42 (m, 10H, phenyl H), 7.62 (br, 2H, NH),
9.44 ppm (br, 2H, NHPh).
1,3-Diallylthiourea (4c).
This compound had mp: 48-50° (Lit. [24], 48-49°).
N-Phenyl-2-thioxotetrahydropyrimidine-1(2H)-carbothioamide
(8a).
This compound was obtained as colourless crystals
(acetonitrile), mp: 150-152°; ir: broad NH 3171, (NH def. and
C-N str.) 1556, (C=S, C-N) 1360, 992 cm-1, (CCl4, 10-3 M, d =
3 cm) (broad NH assoc.) 3188 and (C=S, C-N) 1336, 972 cm-1;
1H nmr: 1.68-1.76 (m, 2H, 5-H2), 3.08 (m, 2H, 6-H2), 3.48 (m,
2H, 4-H2) 7.08-7.11, 7.29-7.32 and 7.36-7.38 (m, 5H, phenyl H),
7.48 (br, s, 1H, 3-NH), 9.54 ppm (br, s, 1H, NHPh), the latter
two signals fade upon treatment of the DMSO-d6 solution with
D2O; 13C nmr: 31.20 (C-5), 50.40 (C-6), 55.80 (C-4), 123.22,
N,N''-1,4-Hexanediylbis[N'-(phenylmethyl)thiourea] (7b).
This compound was obtained as colourless crystals (ethanol),
yield (76%), mp 154-156°. Ir: NH 3328, 3221, (NH def. and C-
1
N str.) 1568, (C=S, C-N) 1368, 996 cm-1; H nmr: 1.26 (m, 4H,
CH2), 1.47 (m, 4H, CH2), 3.36-3.44 (m, 4H, CH2), 4.65 (br, 4H,
CH2Ph), 7.21-7.41 (m, 10H, phenyl H), 7.49 (br, s, 2H, NH),
7.80 ppm (br, s, 2H, NH). ms: m/z 414 (M+, 11), 307 (8), 265
(12), 200 (18), 149 (77), 91 (100), 77 (46).

May-Jun 2006
Thermolysis of N,N''-1,ꢀ-Alkanediyl-bis[N'-organylthiourea] Derivatives)
597
124.25, 128.70 (phenyl CH), 139.10 (phenyl C-1), 175.60
(acyclic C=S), 180.27 ppm (cyclic C=S); ms: m/z 251 (M+, 4),
135 (21), 116 (100), 93 (20), 77 (17), 59 (23).
Anal. Calcd. for C11H13N3S2 (251.37): C, 52.56; H, 5.21; N,
16.72; S, 25.51. Found C, 52.69; H, 5.32; N, 16.58; S, 25.64 %.
This compound was obtained as colourless crystals
(acetonitrile), mp 138-140°, ir: NH 3260, 3170, (NH def. and C-
N str.) 1562, (C=S, C-N) 1350, 975 cm-1; 1H nmr: 1.66-1.70 (m,
2H, 5-H2), 3.20 (m, 2H, 4-H2), 3.34 (m, 2H, 6-H2), 4.00 (br, 2H,
allyl 1-H2), 5.03-5.15 (m, 2H, allyl 3-H2), 5.76-5.88 (m, 1H,
allyl 2-H), 7.46 (br, 1H, allyl-NH), 7.54 ppm (br, 1H, 3-NH);
ms: m/z 215 (M+, 7), 116 (41), 99 (90), 56 (96), 41 (100).
N-Benzyl-2-thioxotetrahydropyrimidine-1(2H)-carbothioamide
(8b).
Anal. Calcd. for C8H13N3S2 (215.34): C, 44.62; H, 6.08; N,
19.51; S, 29.78. Found C, 44.46; H, 6.19; N, 19.44; S, 29.91 %.
This compound was obtained as colourless crystals (ethanol),
mp 54-56°; ir: NH 3220, (NH def. and C-N str.) 1568, (C=S, C-
9-Phenylamino-2,3,4,5,6,7-hexahydro-1,3,8-thiadiazonine-2-
thione (11a).
1
N) 1358, 986 cm-1; H nmr: 1.64-1.76 (m, 2H, 5-H2), 3.09 (m,
2H, 6-H2), 3.36 (m, 2H, 4-H2), 4.61 (m, 2H, CH2Ph), 7.12-7.36
(m, 5H, phenyl H), 7.46 (br, 1H, 3-NH), 7.83 ppm (br, s, 1H,
NHCH2Ph); 13C nmr: 30.80 (C-5), 46.80 (CH2Ph), 50.20 (C-6),
55.70 (C-4), 126.52, 127.40, 128.10 (phenyl CH), 141.63
(phenyl C-1), 175.58 (acyclic C=S), 180.12 (2-C=S); ms: m/z
265 (M+, 7), 178 (12), 149 (51), 116 (62), 91 (100).
This compound was obtained as colourless crystals
(acetonitrile), mp 162-164°; ir NH 3260, 3164, week; C=N
1620, (NH def. and C-N str.) 1541, (C=S, C-N) 1308, 1256 cm-1;
1H nmr: 1.57 (m, 4H, 5-H2 and 6-H2), 3.32 (m, 2H, 4-H2), 3.49
(m, 2H, 7-H2) 7.12-7.41 (m, 5H, phenyl H), 7.78 (br, 1H, 3-NH),
9.48 ppm (br, 1H, NHPh); 13C nmr: 30.59 (C-5,6), 43.79 (C-4),
44.97 (C-7), 124.25, 125.09, 128.81 (phenyl CH), 139.42
(phenyl C-1), 151.64 (C-9), 183.46 ppm (C=S); ms: m/z 265
(M+, 6), 189 (4), 135 (62), 130 (8), 91 (100), 77 (42), 65 (44).
Anal. Calcd. for C12H15N3S2 (265.40): C, 54.31; H, 5.70; N,
15.83; S, 24.16. Found C, 54.46; H, 5.52; N, 15.71; S, 24.33 %.
Anal. Calcd. for C12H15N3S2 (265.07): C, 54.31; H, 5.70; N,
15.83; S, 24.16. Found C, 54.19; H, 5.83; N, 15.91; S, 24.04 %.
N-Allyl-2-thioxotetrahydropyrimidine-1(2H)-carbothioamide (8c).
This compound was obtained as colourless crystals (ethanol),
mp 124-126°; ir: NH 3210, (NH def. and C-N str.) 1570, (C=S,
C-N) 1362, 976 cm-1; 1H nmr: 1.68-1.70 (m, 2H, 5-H2), 3.02 (m,
2H, 6-H2), 3.34 (m, 2H, 4-H2), 4.10 (br, 2H, allyl 1–H2), 5.06-
5.18 (m, 2H, allyl 3-H2), 5.77-5.90 (m, 1H, allyl 2-H), 7.46 (br,
1H, allyl-NH), 7.54 ppm (br, 1H, 3-NH); ms: m/z 215 (M+, 4),
200 (51), 158 (32), 116 (32), 99 (84), 56 (96), 41 (100).
9-Phenylmethylamino-2,3,4,5,6,7-hexahydro-1,3,8-thiadiazonine-
2-thione (11b).
This compound was obtained as colourless crystals (ethanol),
mp 168-170°; ir: NH 3225, (NH def. and C-N str.) 1558, (C=S,
C-N) 1351, 964 cm-1; 1H nmr: 1.46 (m, 4H, 5-H2 and 6-H2), 3.34
(m, 2H, 4-H2), 3.41 (m, 2H, 7-H2), 4.64 (br, 2H, CH2Ph) 7.19-
7.34 (m, 5H, phenyl H), 7.51 (br, 1H, 3-NH), 7.79 ppm (br, 1H,
NHCH2Ph); 13C nmr: 30.60 (C-5,6), 40.52 (C-4), 43.36 (C-7),
126.94, 127.41, 128.40 (phenyl CH), 139.33 (phenyl C-1),
151.63 (C-9), 182.68 ppm (C=S); MS: m/z 279 (M+, 4), 203 (3),
149 (48), 130 (12), 106 (66), 91 (100), 77 (36), 65 (38).
Anal. Calcd. for C8H13N3S2 (215.34): C, 44.62; H, 6.08; N,
19.51; S, 29.78. Found C, 44.79; H, 6.16; N, 19.38; S, 29.61 %.
8-Phenylamino-3,4,5,6-tetrahydro-1,3,7-thiadiazocine-2-thione
(10a).
This compound was obtained as colourless crystals (ethanol),
mp 112-114°; ir: NH 3210, 3190, (NH def. and C-N str.) 1560,
1
Anal. Calcd. for C13H17N3S2 (279.43): C, 55.88; H, 6.13; N,
15.04; S, 22.95. Found C, 55.71; H, 5.98; N, 14.91; S, 23.12 %.
(C=S, C-N) 1366, 992 cm-1; H nmr: 1.78-1.82 (m, 2H, 5-H2),
3.05 (m, 2H, 4-H2), 3.37 (m, 2H, 6-H2) 7.10-7.39 (m, 5H, phenyl
H), 7.80 (br, 1H, 3-NH), 9.54 ppm (br, 1H, NHPh); 13C nmr:
30.22 (C-5), 39.90 (C-4), 42.70 (C-6), 112.66, 126.40, 128.90
(phenyl CH), 139.60 (phenyl C-1), 151.20 (C-8), 184.60 ppm
(C=S); ms: m/z 251 (M+, 7), 135 (88), 116 (41), 93 (100), 77
(71), 51 (42).
9-(2-Propenyl)amino-2,3,4,5,6,7-hexahydro-1,3,8-thiadiazonine-
2-thione (11c).
This compound was obtained as colourless crystals (ethanol),
mp 144-146°; ir: NH 3266, 3164, (NH def. and C-N str.) 1541,
(C=S, C-N) 1356, 1016 cm-1; 1H nmr: 1.46 (m, 4H, 5-H2 and 6-
H2), 3.36 (m, 2H, 4-H2), 3.46 (m, 2H, 7-H2) 4.03 (br, 2H, allyl 1-
H2), 5.05-5.16 (m, 2H, allyl 3-H2), 5.77-5.90 (m, 1H, allyl 2-H),
7.36 (br, 1H, 3-NH), 7.47 ppm (br, 1H, allyl-NH); 13C nmr :
29.51 (C-5,6), 40.50 (C-4), 45.50 (C-7), 43.48 (allyl C-1),
115.46 (allyl C-3), 135.39 (allyl C-2), 151.80 (C-9), 182.10 ppm
(C=S); ms: m/z 229 (M+, 3), 172 (6), 153 (32), 130 (12), 99
(73), 56 (98), 41 (100).
Anal. Calcd. for C11H13N3S2 (251.37): C, 52.56; H, 5.21; N,
16.72; S, 25.51. Found C, 52.41; H, 5.32; N, 16.54; S, 25.67 %.
8-Benzylamino-3,4,5,6-tetrahydro-2H-1,3,7-thiadiazocine-2-
thione (10b).
This compound was obtained as colourless crystals (methanol),
mp 138-140°; ir: NH 3230, 3190, (NH def. and C-N str.) 1568,
(C=S, C-N) 1356, 996 cm-1; 1H nmr: 1.72-1.77 (m, 2H, 5-H2), 3.10
(m, 2H, 4-H2), 3.39 (m, 2H, 6-H2), 4.63 (br, 2H, CH2Ph), 7.22-
7.34 (m, 5H, phenyl H), 7.50 (br, 1H, 3-NH), 7.85 ppm (br, 1H,
NHCH2Ph); 13C nmr: 30.26 (C-5), 38.40 (C-4), 43.10 (C-6), 46.66
(CH2Ph), 122.00, 127.36, 128.60 (phenyl CH), 139.24 (phenyl C-
1), 151.90 (C=N), 184.44 ppm (C=S); ms: m/z 265 (M+, 8), 149
(100), 130 (36), 107 (74), 77 (66), 51 (44).
Anal. Calcd. for C9H15N3S2 (299.37): C, 47.13; H, 6.59; N,
18.32; S, 27.96. Found C, 46.96; H, 6.71; N, 18.46; S, 28.12 %.
11-Phenylamino-1-thia-3,10-diazacycloundec-10-ene-2-thione
(12a).
This compound was obtained as colourless crystals
(methanol), mp 98-100°; ir: NH 3235, 3160, (NH def. and C-N
str.) 1566, (C=S, C-N) 1348, 1030 cm-1; 1H nmr: 1.30 (m, 4H, 6-
H2 and 7-H2), 1.54 (m, 4H, 5-H2 and 8-H2), 3.33 (m, 2H, 4-H2),
3.46 (m, 2H, 9-H2), 7.07-7.41 (m, 5H, phenyl H), 7.73 (br, 1H,
3-NH), 9.45 ppm (br, 1H, NHPh); 13C nmr: 26.40 (C-6,7), 28.63,
Anal. Calcd. for C12H15N3S2 (265.07): C, 54.31; H, 5.70; N,
15.83; S, 24.16. Found C, 54.47; H, 5.57; N, 15.69; S, 24.31 %.
Allylamino-3,4,5,6-tetrahydro-2H-1,3,7-thiadiazocine-2-thione
(10c).

598
A. A. Hassan and D. Döpp
Vol 43
[1] A. A. Hassan, A. E. Mourad, K. M. El-Shaieb, A. H. Abou-
Zied and D. Döpp, Heteroatom Chem., 14, 535 (2003).
[2] K. D. Müller and U. W. Gerwarth, J. Organometal. Chem.,
110, 15 (1976).
[3] W. Guendel, DEHYDAG Deutsche Hydrierwerke GmbH,
Ger. Pat., 1,183,069, (1964); Chem. Abstr., 62, 5198e (1965).
[4] B. T. Golding and I. K. Nassereddin, J. Chem. Res. (S), 11,
342 (1981).
28.94 (C-5,8), 43.98, 44.30 (C-4,9), 124.16, 125.09, 128.75
(phenyl CH), 139.51 (phenyl C-1), 151.64 (C-11), 180.44 ppm
(C=S); ms: m/z 293 (M+, 6), 177 (28), 135 (100), 93 (96), 77
(94), 57 (61).
Anal. Calcd. for C14H19N3S2 (293.45): C, 57.30; H, 6.53; N,
14.32; S, 21.85. Found C, 57.44; H, 6.66; N, 14.19; S, 22.02 %.
11-Phenylmethylamino-1-thia-3,10-diazacycloundec-10-ene-2-
thione (12b).
[5] O. Stoutland, L. Helgen and C. L. Agre, J. Org. Chem., 24,
818 (1959).
[6] T.Yabuuchi, M. Hisaki, M. Matuda and R. Kimura, Chem.
Pharm. Bull., 23, 663 (1975).
This compound was obtained as colourless crystals
(acetonitrile), mp 128-130°, ir: NH 3261, 3212, (NH def. and C-
N str.) 1574, (C=S, C-N) 1360, 1014 cm-1; 1H nmr: 1.26 (m, 4H,
6-H2 and 7-H2), 1.47 (m, 4H, 5-H2 and 8-H2), 3.33 (m, 2H, 4-
H2), 3.41 (m, 2H, 9-H2), 4.65 (br, 2H, CH2Ph), 7.21-7.34 (m, 5H,
phenyl-H), 7.48 (br, 1H, 3-NH), 7.78 ppm (br, 1H, NHCH2Ph);
13C nmr: 26.94 (C-6,7), 28.90, 28.94 (C-5,8), 40.26 (C-4), 43.58
(C-9), 47.02 (CH2Ph), 126.92, 127.40, 128.38 (phenyl CH),
139.60 (phenyl C-1), 151.62 (C-11), 182.62 ppm (C=S); ms: m/z
307 (M+, 6), 149 (41), 106 (63), 91 (100), 77 (31), 65 (42).
Anal. Calcd. for C15H21N3S2 (307.48): C, 58.59; H, 6.88; N,
13.67; S, 20.86. Found C, 58.72; H, 7.04; N, 13.53; S, 20.93 %.
[7] H.-O. Kalinowski, S. Berger and S. Braun, 13C-NMR-
Spektroskopie, Stuttgart, Thieme, 1984, p. 189-190.
[8] E. L. Eliel and S. H. Wilen, Stereochemistry of Organic
Compounds, New York, Wiley & Sons, 1994, p. 770.
[9] K. Nakanishi and P. H. Solomon, Infrared Absorption
Spectroscopy, 2nd ed., San Francisco, Holden-Day, 1977, p. 50.
[10] G. Socrates, Infrared Characteristic Group Frequencies,
Chichester, Wiley & Sons ,1980, p. 116-117.
[11a] W. Simons, The Sadtler Handbook of IR Spectra,
Philadelphia, Sadtler Research Labs., 1978; [b] B. Schrader,
Raman/Infrared Atlas of Organic Compounds, 2nd ed., Weinheim, VCH,
1989.
[12] H. Binder, Monatsh. Chem., 98, 431 (1967).
[13] C. Larsen, U. Anthoni, C. Christophersen and P. H. Nielsen,
Acta Chim. Scand., 23, 324 (1969).
[14] A. Hartmann, in Methoden der Organischen Chemie
(Houben-Weyl), Vol. E4 (ed. by H. Hagemann), Stuttgart, Thieme,
1983, p. 834-883.
11-(2-Propenyl)amino-1-thia-3,10-diazacycloundec-10-ene-2-
thione (12c).
This compound was obtained as colourless crystals (ethanol),
mp 80-88°; ir: NH 3244, C=N 1610, (NH def. and C-N str.)
1
1567, (C=S, C-N) 1362, 1024 cm-1; H nmr: 1.27 (m, 4H, 6-H2
[15] A. E. M. Gaber, M. Aly and A. A. Atalla, Coll. Czech. Chem.
Commun., 56, 2183 (1991).
[16] A. E. M. Gaber and O. S. Mohammed, Phosphorus, Sulfur,
Silicon Relat. Elem., 174, 193 (2001).
[17] E. Kühle, in Methoden der Organischen Chemie (Houben-
Weyl), Vol. E4 (ed. by H. Hagemann), Stuttgart, Thieme, 1983, p. 522-
624.
[18] F. Duus, "Thiocarbonyl Compounds", Ch. 11.22 in
Comprehensive Organic Chemistry, Vol. 3 (ed. by D. Neville-Jones),
Oxford, Pergamon Press, 1979, p. 452-461.
and 7-H2), 1.46 (m, 4H, 5-H2 and 8-H2), 3.33 (m, 2H, 4-H2), 3.36
(m, 2H, 9-H2), 4.03 (br, 2H, allyl 1-H2), 5.05-5.16 (m, 2H, 3-H2),
5.77-5.90 (m, 1H, allyl 2-H), 7.31 (br, 1H, 3-NH), 7.44 ppm (br,
1H, allyl-NH); 13C nmr: 26.33 (C-6,7), 28.89, 28.93 (C-5,8),
43.98, 40.25 (C-4), 43.56 (C-9), 45.91 (allyl C-1), 115.06 (allyl
C-3), 135.41 (allyl C-2), 151.61 (C-11), 182.36 ppm (C=S); ms:
m/z 257 (M+, 3), 158 (28), 99 (36), 57 (100), 41 (68).
Anal. Calcd. for C11H19N3S2 (257.42): C, 51.32; H, 7.44; N,
16.32; S, 24.91. Found C, 51.46; H, 7.53; N, 16.21; S, 25.08 %.
[19] A. Hamzé, J. Martinez and J. F. Hernandez, J. Org. Chem.,
69, 8394 (2004).
Acknowledgement.
[20] J. L. Jimenez Blanco, C. Saitz Barria, J. M. Benito, C. Ortiz
Mellet, J. Fuentes, F. Santoyo-Gonzalez and J. M. Garcia Fernandez,
Synthesis, 1907 (1999).
[21] F. Zetsche and A. Fredrich, Ber. Dtsch. Chem. Ges., 73,
1420 (1940).
A. A. Hassan is indebted to the A. v. Humboldt-Foundation
for the award of a fellowship from August 2003 to Sept. 2003
and also for the donation of the Shimadzu 408 IR
spectrophotometer. Financial support of this work by Fonds der
Chemischen Industrie is gratefully acknowledged.
[22] R. Walther and A. Stenz, J. Prakt. Chem., 181 (New series.:
73) 222 (1906).
[23] M. Ballabeni, R. Ballini, F. Bigi, M. Parrini, G. Predieri and
G. Sartori, J. Org. Chem., 64, 1029 (1999).
REFERENCES AND NOTES
[24] P. C. Mohanta, S. Dhar, S. K. Samal, H. Ila and H. Junjappa,
Tetrahedron, 56, 629 (2000).
*
To whom correspondence should be addressed.