Triton-B catalyzed, efficient one-pot synthesis of dithiocarbazates

Article abstract of DOI:10.1007/s00706-008-0873-9

A quick and efficient, one-pot synthesis of dithiocarbazates was accomplished in high yields by the reaction of various primary, secondary, and tert. alkyl halides with a variety of substituted hydrazines using the benzyl-trimethylammonium hydroxide (Triton-B)/CS₂ system. The reaction conditions are mild with simpler work-up procedures than the reported methods.

Full text of DOI:10.1007/s00706-008-0873-9

Monatsh Chem 139, 1033–1036 (2008)
DOI 10.1007/s00706-008-0873-9
Printed in The Netherlands
Triton-B catalyzed, efficient one-pot synthesis of dithiocarbazates
Devdutt Chaturvedi1, Nisha Mishra2, Virendra Mishra2
1
Medicinal and Process Chemistry Division, Central Drug Research Institute, Lucknow, U.P., India
2
Synthetic Research Laboratory, Department of Chemistry, B.S.A. College, Mathura, U.P., India
Received 11 November 2007; Accepted 13 December 2007; Published online 24 July 2008
# Springer-Verlag 2008
Abstract A quick and efficient, one-pot synthesis of
dithiocarbazates was accomplished in high yields
by the reaction of various primary, secondary, and
tert. alkyl halides with a variety of substituted hydra-
zines using the benzyl-trimethylammonium hydrox-
ide (Triton-B)=CS2 system. The reaction conditions
are mild with simpler work-up procedures than the
reported methods.
CS2. However, their formation using CS2 employed
harsh reaction conditions, such as use of strong ba-
ses, high reaction temperatures, and long reaction
times [11]. Thus, we were prompted to embark on
the improved procedures. Our group [12] has been
engaged during the past several years for the devel-
opment of new methodologies for the preparation of
carbamates, dithiocarbamates, and related compounds
using cheap, abundantly available, and safe reagents
like CO2, and CS2. Recently [13], we found that
benzyltrimethyl ammonium hydroxide (Triton-B) is
the best catalyst for the synthesis of carbamates,
dithiocarbamates, and dithiocarbonates (xanthates).
We report here an efficient, one-pot, synthesis of
dithiocarbazates from a variety of primary, second-
ary, and tertiary alkyl halides and substituted hydra-
zines using the Triton-B=CS2 system.
Keywords Alkyl halides; Benzyltrimethylammonium hydrox-
ide;Carbon disulfide; Substituted hydrazines; Dithiocarbazates.
Introduction
Organic dithiocarbazates have received much atten-
tion due to their numerous remarkable medicinal,
industrial, and synthetic applications [1, 2]. They
have extensively been used as pharmaceuticals [3],
agrochemicals [4], intermediates in organic synthe-
sis [5], protection of amino groups in peptide syn-
thesis [6], linkers in solid phase organic synthesis
[7], and as donor ligands in complexation reactions
with transition metals [8]. To satisfy their demand,
their synthesis has been changed from the use of
costly and toxic chemicals like thiophosgene [9]
and its derivatives [10] directly or indirectly, to the
abundantly available cheap and safe reagents like
Results and discussion
A mixture of substituted hydrazine and CS2 were
taken in dry DMSO and Triton-B was added. The
reaction was stirred for 30 min at room temperature,
and then corresponding alkyl halide was added.
The reaction was further continued until comple-
tion as checked by TLC (see Table 1). It is proposed
that the Sꢀ of the dithiocarbazate ion produced will
attack to the electrophilic carbon of the respec-
tive alkyl halide to afford dithiocarbazates in high
yields (78–98%) at room temperature in 2–4 h, as
mentioned in Table 1. The reaction proved to be
Correspondence: Devdutt Chaturvedi, Medicinal and Process
Chemistry Division, Central Drug Research Institute,
Lucknow-226001, U.P., India. E-mail: ddchaturvedi002@
yahoo.co.in

1034
D. Chaturvedi et al.
Scheme 1
Table 1 Conversion of alkyl halides into dithiocarbazates of
formula 1–16
mation of carbon–sulfur bonds essential to numer-
ous organic syntheses.
Entry R1
R2
R3
X
R
Time=
h
Experimental
1
2
3
4
5
6
7
8
n-C3H7
H
H
H
H
Me
H
H
H
H
C4H9
H
H
H
H
H
H
H
H
H
H
Br 4-MeO–Ph
Br Ph
Cl Ph
Cl Bn
Br Bn
Cl Ph-3-NO2
Br Ph-4NO2
Br Ph-2,4-NO2
Br naphthyl
Br Ph
2
2
2.5
3
3
3
3
4
3
Chemicals were procured from Merck, Aldrich, and Fluka
chemical companies. Reactions were carried out under an
atmosphere of Argon. IR spectra 4000–200 cmꢀ1 were re-
corded on Bomem MB-104-FTIR spectrophotometer using
neat technique, where as NMRs were scanned on AC-300F,
NMR (300 MHz), instrument using CDCl3 and some other
deutrated solvents and TMS as internal standard. Elemental
analysis were conducted by means of a Carlo-Erba EA
1110-CNNO-S analyzer and agreed favorably with calcu-
lated values.
PhCH2CH2
PhCH2
Ph
C2H5
Ph-4-MeO
C3H7
C3H7
C3H7
C4H9
C4H9
C5H11
C7H15
C9H19
C3H7
9
10
11
12
13
14
15
16
3
3
C4H9 C4H9 Br Ph
H
H
H
C3H7
CH3
H
H
H
H
H
Cl n-C4H9
Cl Ph
Cl n-C4H9
Br Ph
Br Ph
2.5
2.5
2
3
3.5
Typical experimental procedure
To a stirred solution (under Ar) of 3 mmol substituted hy-
drazine in 5 cm3 anhyd. DMSO was slowly added, 8 cm3 car-
bon disulfide, and 2 cm3 Triton-B at room temperature. Then
the mixture was stirred for 0.5 h at which point 3 cm3 of
the required alkyl halide was added over a period of 5 min.
The stirring was further continued till the completion of re-
action (cf Table 1). The reaction mixture was poured into
20cm3 water and organic layer was extracted with 3ꢁ10 cm3
EtOAc. The organic layer was washed with 20cm3 0.1 N HCl,
25cm3 saturated solution of NaHCO3, 30 cm3 brine, and
then dried (Na2SO4) and concentrated to get the desired com-
pound.
Ph
a
All the products were characterized by IR, NMR, and mass
spectroscopic data
b
Isolated yields
successful and the desired products were isolated
and their structures confirmed by various spectro-
scopic and analytical techniques. The whole reaction
conditions are shown in Scheme 1.
Butyl 2-(4-methoxyphenyl)hydrazinecarbodithioate
We tried several solvents like n-heptane, n-hexane,
acetonitrile, benzene, toluene, methanol, dichloro-
methane, chloroform, DMSO, dimethylformamide,
hexamethylphosphoric triamide of which dry DMSO
proved to be most suitable at room temperature.
In conclusion, we developed a convenient and ef-
ficient protocol for the one-pot, three components
coupling of various amines with a variety of primary,
secondary, and tertiary alkyl halides via CS2 bridge
using Triton-B. This method generates the corre-
sponding dithiocarbazates in good to excellent yields.
Furthermore, this method exhibits substrate versa-
tility, mild reaction conditions, and experimental
convenience. This synthesis protocol developed is
believed to offer a more general method for the for-
(1, C12H18N2OS2)
Yield 93%; mp yellow oil; IR (neat): ꢀꢀ¼ 675, 1210cmꢀ1
;
1H NMR (CDCl3): ꢁ ¼ 0.85 (t, 3H, J ¼ 7.3 Hz), 1.33 (m, 2H),
1.85 (m, 2H), 2.0 (s, NH), 2.95 (t, 2H, J ¼ 6.3 Hz), 3.73 (s,
3H), 4.05 (m, NH), 6.75–7.60 (m, 4H) ppm; 13C NMR
(CDCl3): ꢁ ¼ 13.5, 21.8, 32.4, 33.9, 43.7, 55.6, 112.5, 114.9,
134.5, 152.4, 222.5 (C¼S) ppm; MS (EI): m=z ¼ 270.
3-Phenylpropyl 2-phenylhydrazinecarbodithioate
(2, C16H18N2S2)
Yield 96%; mp yellow oil; IR (neat): ꢀꢀ¼ 676, 1205 cmꢀ1
;
1H NMR (CDCl3): ꢁ ¼ 2.05 (s, H, NH), 2.30 (m, 2H,
Phꢂ CH2 ꢂ CH2 ꢂ CH2–S), 2.56 (t, 2H, J ¼ 7.2 Hz, Ph ꢂ CH2),
2.87 (t, 2H, Phꢂ CH2 ꢂ CH2 ꢂ CH2 ꢂ S), 4.03 (m, H, Phꢂ NH),
6.66–7.12 (m, 10H, Ar–H) ppm; 13C NMR (CDCl3): ꢁ ¼
32.2, 33.6, 34.4, 112.5, 119.2, 125.8, 128.6, 129.5, 138.6,
221.6 (C¼S) ppm; MS: m=z ¼ 302.

Efficient one-pot synthesis of dithiocarbazates
1035
1.97 (m, 2H, SCH2 ꢂ CH2), 2.05 (br, H, NH), 2.84 (t, 2H,
SCH2), 4.05 (br, N, NHArNO2), 6.76–7.55 (m, 7H, Ar–H)
ppm; 13C NMR (CDCl3): ꢁ ¼ 13.9, 22.1, 32.5, 33.9, 107.4,
117.2, 121.3, 124.5, 126.6, 127.2, 133.5, 142.6, 224.1 ppm;
MS: m=z ¼ 290.
2-Phenylethyl 2-phenylhydrazinecarbodithioate
(3, C15H16N2S2)
Yield 86%; mp yellow oil; IR (neat): ꢀꢀ¼ 673, 1203 cmꢀ1; 1H
NMR (CDCl3): ꢁ ¼ 2.10 (s, H, NH), 3.20 (2H, t, J ¼ 6.5 Hz,
Phꢂ CH2CH2S), 3.24 (m, 2H, J ¼ 7.2 Hz, PhCH2), 4.52 (m, H,
PhNH), 6.69–7.15 (m, 10H, Ar–H) ppm; 13C NMR (CDCl3):
ꢁ ¼ 34.5, 37.3, 47.2, 49.9, 118.6, 192.7, 223.3 (C¼S) ppm;
MS: m=z ¼ 288.
1-Butylpentyl 2-phenylhydrazinecarbodithioate
(10, C16H26N2S2)
Yield 88%; mp yellow oil; IR (neat): ꢀꢀ¼ 677, 1212cmꢀ1
;
1H NMR (CDCl3): ꢁ ¼ 0.96 (t, 6H, CH3), 1.29 (m, 4H,
CH2CH2CH), 1.33 (m, 4H, CH2CH3), 1.92 (m, 4H,
CHCH2), 2.05 (br, H, NH), 2.52 (t, H, SCH), 4.05 (br, H,
NHAr), 6.66–7.18 (m, 5H, Ar–H) ppm; 13C NMR (CDCl3):
ꢁ ¼ 14.2, 23.1, 28.5, 36.2, 41.4, 112.2, 119.3, 129.0, 142.4,
223.3 ppm; MS: m=z ¼ 310.
Benzyl 2-butylhydrazinecarbodithioate (4, C12H18N2S2)
Yield 91%; mp yellow oil; IR (neat): ꢀꢀ¼ 676, 1207 cmꢀ1; 1H
NMR (CDCl3): ꢁ ¼ 1.05 (t, 3H, CH3), 1.33 (m, 2H, CH2CH3),
1.56 (m, 2H, CH2 ꢂ CH2CH3), 2.05 (br, NH), 2.65 (m, 2H,
NHCH2), 4.13 (s, 2H, PhCH2), 7.06–7.15 (m, 5H, Ar–H)
ppm; 13C NMR (CDCl3): ꢁ ¼ 13.7, 20.2, 31.5, 38.5, 50.9,
126.8, 127.6, 128.5, 141.8, 223.5ppm; MS: m=z ¼ 254.
1,1-Dibutylpentyl 2-phenylhydrazinecarbodithioate
(11, C20H34N2S2)
sec-Butyl 2-butylhydrazinecarbodithioate (5, C9H20N2S2)
Yield 86%; mp yellow oil; IR (neat): ꢀꢀ¼ 669, 1210cmꢀ1; 1H
NMR (CDCl3): ꢁ ¼ 0.96 (t, 6H, CH3), 1.29 (m, 4H, CH2-
CH2C), 1.33 (m, 4H, CH2CH3), 1.88 (m, 4H, CHCH2), 2.04
(br, H, NH), 4.0 (br, H, NH–Ar), 6.67–7.19 (m, 5H, Ar–H)
ppm; 13C NMR (CDCl3): ꢁ ¼ 14.1, 23.4, 26.7, 39.6, 41.1,
112.5, 119.3, 129.6, 142.2, 223.5 ppm; MS: m=z ¼ 366.
Yield 89%; mp IR (neat): ꢀꢀ¼ 682, 1214 cmꢀ1
;
1H NMR
(CDCl3): ꢁ ¼ 0.99 (t, 3H, CH3), 1.05 (t, 3H, CH3), 1.35
(m, 2H, CH2 ꢂ CH3), 1.41 (d, 3H, CHCH3), 1.55 (m, 2H,
CH3CH2CH2), 1.96 (m, 2H, CHCH2), 2.0 (br, H, NH), 2.65
(m, 2H, NHCH2), 2.70 (m, H, CH–S) ppm; 13C NMR
(CDCl3): ꢁ ¼ 10.2, 13.7, 20.2, 21.5, 31.2, 32.3, 40.1, 49.9,
223.4ppm; MS: m=z ¼ 220.
Hexyl 2-butylhydrazinecarbodithioate (12, C11H24N2S2)
Yield 95%; mp yellow oil; IR (neat): ꢀꢀ¼ 674, 1208cmꢀ1
;
4-Methoxybenzyl 2-(3-Nitrophenyl)hydrazinecarbodithioate
1H NMR (CDCl3): ꢁ ¼ 0.96 (t, 6H, CH3), 1.29 (m, 4H,
CH2CH2CH2CH3), 1.33 (t, 2H, CH2CH3), 1.55 (m, 2H,
NHCH2CH2), 1.96 (m, 2H, SCH2CH2), 2.0 (br, 2H, NH),
2.65 (t, 2H, NHCH2), 2.87 (t, 2H, SCH2) ppm; 13C NMR
(CDCl3): ꢁ ¼ 13.7, 14.1, 20.2, 23.1, 28.6, 31.5, 32.6, 49.9,
223.1 ppm; MS: m=z ¼ 248.
(6, C15H15N3O3S2)
Yield 84%; mp yellow oil; IR (neat): ꢀꢀ¼ 678, 1211 cmꢀ1
;
1H NMR (CDCl3): ꢁ ¼ 2.05 (br, H, NHPhꢂ OMe), 3.73 (s,
3H, OCH3), 4.06 (br, H, NHPhꢂ NO2), 6.65–7.66 (m, 8H,
Ar–H) ppm; 13C NMR (CDCl3): ꢁ ¼ 38.3, 56.7, 107.5, 114.6,
118.4, 128.5, 129.9, 133.6, 143.6, 148.7, 160.6, 223.2 ppm;
MS: m=z ¼ 349.
n-Octyl 2-phenylhydrazinecarbodithioate (13, C15H24N2S2)
Yield 96%; mp yellow oil; IR (neat): ꢀꢀ¼ 679, 1211cmꢀ1
;
1H NMR (CDCl3): ꢁ ¼ 0.96 (t, 3H, CH3), 1.29 (m, 8H,
CH2), 1.33 (m, 2H, CH2CH3), 1.96 (m, 2H, SCH2CH2), 2.0
(br, H, NH), 2.88 (t, 2H, SCH2), 4.0 (br, H, Phꢂ NH), 6.65–
7.20 (m, 5H, Ar–H) ppm; 13C NMR (CDCl3): ꢁ ¼ 14.5, 23.10,
28.9, 30.5, 31.5, 32.5, 112.2, 129.6, 118.9, 142.2, 223.6 ppm;
MS: m=z ¼ 296.
Butyl 2-(4-nitrophenyl)hydrazinecarbodithioate
(7, C11H15N3O2S2)
Yield 84%; mp yellow oil; IR (neat): ꢀꢀ¼ 666, 1203 cmꢀ1; 1H
NMR (CDCl3): ꢁ ¼ 0.96 (t, 3H, CH3), 1.33 (m, 2H, CH2CH3),
1.96 (m, 2H, SCH2 ꢂ CH2), 2.05 (br, H, NH), 2.87 (t, 2H,
SCH2), 4.04 (br, N, NHArNO2), 6.92–8.15 (m, 4H, Ar–H)
ppm; 13C NMR (CDCl3): ꢁ ¼ 13.7, 21.6, 32.2, 33.7, 113.5,
124.6, 138.8, 143.3, 223.5 ppm; MS: m=z ¼ 285.
Decyl 2-butylhydrazinecarbodithioate (14, C15H32N2S2)
Yield 98%; mp yellow oil; IR (neat): ꢀꢀ¼ 673, 1220cmꢀ1
;
1H NMR (CDCl3): ꢁ ¼ 0.97 (s, 3H, CH3), 0.99 (s, 3H,
CH3), 1.29 (m, 12H, CH2), 1.34 (m, 4H, CH2CH3), 1.55
(m, 2H, CH2CH2CH3), 1.96 (m, 2H, SCH2CH2), 2.0 (br,
2H, NH ꢂ NH), 2.65 (m, 2H, NHCH2), 2.87 (t, 2H, SCH2)
ppm; 13C NMR (CDCl3): ꢁ ¼ 13.7, 14.5, 20.3, 23.1, 28.9,
30.6, 30.9, 31.5, 32.5, 222.1 ppm; MS: m=z ¼ 304.
Butyl 2-(2,4-dinitrophenyl)hydrazinecarbodithioate
(8, C11H14N4O4S2)
Yield 78%; mp yellow oil; IR (neat): ꢀꢀ¼ 670, 1212 cmꢀ1; 1H
NMR (CDCl3): ꢁ ¼ 0.94 (t, 3H, CH3), 1.32 (m, 2H, CH2CH3),
1.95 (m, 2H, SCH2 ꢂ CH2), 2.02 (br, H, NH), 2.83 (t, 2H,
SCH2), 4.04 (br, N, NHArNO2), 7.19–9.50 (m, 3H, Ar–H)
ppm; 13C NMR (CDCl3): ꢁ ¼ 13.8, 21.9, 32.3, 33.8, 113.6,
119.2, 130.2, 132.8, 139.7, 143.3, 222.5ppm; MS: m=z ¼ 330.
1-Propylbutyl 2-phenylhydrazinecarbodithioate
(15, C14H22N2S2)
Yield 85%; mp yellow oil; IR (neat): ꢀꢀ¼ 675, 1210cmꢀ1; 1H
NMR (CDCl3): ꢁ ¼ 0.97 (s, 3H, CH3), 1.33 (m, 4H, CH2CH3),
1.92 (m, 4H, CHCH2), 2.0 (br, H, NH), 2.52 (m, H, CH–S),
4.1 (br, H, NH–Ar), 6.66–7.22 (m, 5H, Ar–H) ppm; 13C NMR
Butyl 2-(naphth-2-yl)hydrazinecarbodithioate
(9, C15H18N2S2)
Yield 82%; mp yellow oil; IR (neat): ꢀꢀ¼ 677, 1209 cmꢀ1; 1H
NMR (CDCl3): ꢁ ¼ 0.95 (t, 3H, CH3), 1.33 (m, 2H, CH2CH3),

1036
D. Chaturvedi et al.
(CDCl3): ꢁ ¼ 14.5, 20.1, 38.4, 40.8, 112.5, 118.3, 129.6, 143.3,
222.1 ppm; MS: m=z ¼ 282.
K, Miyoshi M, Ohnishi T, Okumura K (1969) Bull Chem
Soc Jpn 42:809; c) Quibell M, Turnell WG, Johnson T
(1993) J Chem Soc Perkin Trans I 22:2843; d) Gray CJ,
Quibell M, Baggett N, Hammerle T (1992) Int J Pept
Protien Res 40:351
1-Phenylethyl 2-phenylhydrazinecarbodithioate
(16, C15H16N2S2)
Yield 82%; mp yellow oil; IR (neat): ꢀꢀ¼ 678, 1210 cmꢀ1
;
7. a) Huang JY, Choi HS, Lee DH, Yoo SE, Gong YD (2005)
J Comb Chem 7:136; b) Hwang JY, Choi HS, Lee DH,
Gong YD (2005) J Comb Chem 7:816
8. a) Bolzati C, Benini E, Cavazza-Ceccato M, Cozzala E,
Malago E, Agostini S, Tisato F, Rofosco F, Bandoli G
(2006) Bioconjugate Chem 17:419; b) Ali MA, Mirza
AH, Butcher RJ, Krause KA (2006) Transition Metal
Chemistry 31:79; c) Singh R, Kaushik NK (2004) Main
Group Metal Chemistry 27:327
1H NMR (CDCl3): ꢁ ¼ 1.69 (d, 3H, CH3), 2.2 (br, H, NH),
3.98 (m, H, CH–S), 4.2 (br, H, NH–Ar), 6.66–7.22 (m, 10H,
Ar–H) ppm; 13C NMR (CDCl3): ꢁ ¼ 23.4, 41.1, 112.5, 118.9,
126.5, 128.5, 129.7, 141.3, 142.5, 222.1ppm; MS: m=z ¼ 288.
Acknowledgements
Authors wish to thank SIAF division of CDRI for providing
spectroscopic and analytical data.
9. Dyker H, Scherkenbeck J, Gondol D, Goehrt A, Harder A
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