Preparation of N-substituted aryl and alkyl carbamates and their inhibitory effect on oat seed germination.

Article abstract of DOI:10.1271/bbb.66.422

A series of N-substituted aryl and alkyl carbamates (RNHCOOR'; R: aryl, alkyl; R': aryl, alkyl) was prepared and screened for inhibitory activity toward the germination of oat seeds. The activity of each compound was compared with that of chlorpropham (isopropyl 3-chlorocarbanilate). Some of the synthetic carbamates possessing the N-(phenylthio)methyl group, PhSCH2NHCOOR', showed inhibitory activity close or comparable to that of chlorpropham.

Full text of DOI:10.1271/bbb.66.422

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Preparation of N-Substituted Aryl and Alkyl
Carbamates and Their Inhibitory Effect on Oat Seed
Germination
Babak Heidary ALIZADEHa, Takeyoshi SUGIYAMAa, Takayuki ORITANIa & Shigefumi
KUWAHARAa
a Laboratory of Applied Bioorganic Chemistry, Graduate School of Agricultural Science,
Tohoku University 1-1 Tsutsumidori-Amamiyamachi, Aoba-ku, Sendai 981-8555, Japan
Published online: 22 May 2014.
To cite this article: Babak Heidary ALIZADEH, Takeyoshi SUGIYAMA, Takayuki ORITANI & Shigefumi KUWAHARA (2002)
Preparation of N-Substituted Aryl and Alkyl Carbamates and Their Inhibitory Effect on Oat Seed Germination, Bioscience,
Biotechnology, and Biochemistry, 66:2, 422-425, DOI: 10.1271/bbb.66.422
To link to this article: http://dx.doi.org/10.1271/bbb.66.422
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Biosci. Biotechnol. Biochem., 66 (2), 422–425, 2002
Note
Preparation of
N-Substituted Aryl and Alkyl Carbamates and Their
Inhibitory EŠect on Oat Seed Germination
Babak Heidary ALIZADEH,† Takeyoshi SUGIYAMA, Takayuki ORITANI
and Shigefumi KUWAHARA
,
Laboratory of Applied Bioorganic Chemistry, Graduate School of Agricultural Science,
Tohoku University, 1-1 Tsutsumidori-Amamiyamachi, Aoba-ku, Sendai 981-8555, Japan
Received July 3, 2001; Accepted October 25, 2001
A series of
(RNHCOOR
N
-substituted aryl and alkyl carbamates
aromatic moiety attached to the oxygen atom by add-
ing methylene unit(s) to the O-phenyl bond of I-1.
The phenyl isocyanate derived from benzoic acid was
?
; R: aryl, alkyl; R : aryl, alkyl) was
?
prepared and screened for inhibitory activity toward the
germination of oat seeds. The activity of each com-
pound was compared with that of chlorpropham
(isopropyl 3-chlorocarbanilate). Some of the synthetic
carbamates possessing the
PhSCH2NHCOOR , showed inhibitory activity close or
allowed to react with some
v-phenylalkyl alcohols to
give carbamates II-1–II-5. Another carbamate pos-
sessing a double bond on the linking chain (II-6) was
also prepared. Among this type of carbamates, com-
pound II-2 exhibited considerable inhibitory activity
against the growth of both the coleoptile and roots,
and compound II-6 showed a similar level of activity
against root growth, although their eŠectiveness was
not promising enough for use as practical herbicides.
We next turned our attention to the somewhat
N-(phenylthio)methyl group,
?
comparable to that of chlorpropham.
Key words: carbamate; germination inhibitor; isoc-
yanate;
N-(phenylthio)methylcarbamate
N
-Substituted carbamic acid esters (RNHCOOR
?)
drastic modiˆcation of the
Table 1), and displaced the
carbamates II by -(phenylthio)methyl which con-
tains a sulfur atom. Based on the observation that
carbamate II-2 with an -2-phenylethyl group
showed considerable activity, carbamate III-3 pos-
sessing the same -substituent was ˆrst prepared and
N
-substituent (R in
are widely used as insecticides and herbicides in
agriculture.1) Carbanilic acid aliphatic esters such as
chlorpropham (1) and propham (2) (isopropyl car-
banilate) are selective pre- and post-emergence herbi-
cides that are used for the control of annual grasses
and broad-leaf species among a variety of tolerant
crops (Fig. 1).2) Swep (3; methyl 3,4-dichlorocarbani-
late) is also used in rice production in Japan.2) We at-
tempt in this study to ˆnd new herbicidal carbamates
N-phenyl substituent in
N
O
O
evaluated for its eŠect on oat germination. As shown
in Table 2, III-3 showed potent inhibitory activity
comparable to that of chlorpropham at a concentra-
by changing the
the above-mentioned herbicides.
O
-alkyl and
N
-aryl substituents of
tion of 1
m
M
. Encouraged by this desirable result, we
-(phenylthio)methyl carba-
prepared a series of
N
The carbamate derivatives prepared in this study
are shown in Table 1. First, a variety of aromatic car-
boxylic acids were converted into carbamates I-1–I-5
by reacting the corresponding isocyanate with phenol
(Table 1, Method A),3–5) and their inhibitory activity
toward the germination of oat seeds was evaluated.
mates (III-1, III-2, and III-4–III-7) by treating the
corresponding carboxylic acids with DPPA and then
reacting the resulting acyl azides with various alco-
hols or phenols (Table 2, Method B).6,7) As shown in
As shown in Table 2, these
O-phenyl carbamates pos-
sessing various -aryl groups had poor inhibitory ac-
N
tivity against the growth of both the coleoptile and
roots. The introduction of an electron-donating (I-2
and I-3) or electron-withdrawing group (I-4 and I-5)
to the
N-phenyl substituent of I-1 did not lead to any
improvement in the activity of I-1 possessing the sim-
plest structure. We next investigated the eŠect of the
distance between the carbamoyl functionality and
Fig. 1. Structures of Typical Herbicidal Carbamates.
†
To whom correspondence should be addressed. Tel: +81-22-717-8785; Fax: +81-22-717-8783; E-mail: babak
＠
biochem.tohoku.ac.jp
Abbreviation: DPPA, diphenylphosphoryl azide

Preparation and Activity of
N
-Substituted Carbamates
423
Table 1. Preparation of the Carbamate Derivatives
Carbamate
R
R?
Carbamate
R
R?
I-1
I-2
I-3
I-4
Ph
-MePh
Ph
Ph
Ph
Ph
Ph
III-1#
III-2
III-3
III-4
III-5
III-6
III-7
III-8
III-9
III-10
III-11
III-12
PhSCH2
PhSCH2
PhSCH2
PhSCH2
PhSCH2
PhSCH2
PhSCH2
PhSCH2
PhSCH2
PhSCH2
PhSCH2
PhSCH2
Ph
PhCH2
Ph(CH2)2
Ph(CH2)3
2,4-Cl2Ph
m
p
p
p
-MeOPh
-ClPh
-FPh
I-5
II-1
II-2
II-3
II-4
II-5
II-6
IV
Ph
Ph
Ph
Ph
Ph
Ph
Ph(CH2)2
PhCH2
p-MeOPhCH2
＝
Ph(CH2)2
Ph(CH2)3
Ph(CH2)4
Ph(CH2)5
PhCH CHCH2
PhCH2
PhCH CHCH2
CH3
CH3CH2
CH3(CH2)2
(CH3)2CH
CH3(CH2)3
＝
*
Method A: 1) RCO2H, SOCl2, toluene, re‰ux; 2) NaN3, toluene, rt; 3) toluene, re‰ux; 4) R?OH, Et3 N, THF, rt. This method was applied for the prepara-
tion of compounds I-1–I-5 and II-1–II-6.
Method B: 1) DPPA, Et3N, toluene, rt; 2) R
?OH, Et3N, THF, rt. This method was applied for the preparation of compounds III-1–III-12 and IV.
#
New compounds are underlined.
some improvement in the activity of II-6 by introduc-
ing a double bond to II-3, might also imply the im-
portance of the distance between the two functional
groups.
Table 2. EŠects of the Synthetic Carbamates on the Germination
of Oat Seeds at a Concentration of 1
mM
*
Carbamate
C#
R#
Carbamate
C
R
untreated
chlorpropham
9.5
0.0
4.7
5.6
8.3
8.1
6.4
2.8
0.3
3.5
4.9
6.6
3.4
7.0
0.0
1.9
4.4
7.7
4.1
4.8
1.2
0.2
1.9
1.2
2.1
0.4
III-1
III-2
III-3
III-4
III-5
III-6
III-7
III-8
III-9
III-10
III-11
III-12
IV
0.0
0.0
0.0
4.6
0.0
1.4
2.2
0.0
0.8
1.7
0
0.0
0.0
0.0
3.9
0.0
0.9
2.6
0.0
1.0
1.4
0.0
3.4
2.8
We next examined the inhibitory activity of
(phenylthio)methyl carbamates containing a simple
-alkyl substituent (III-8–III-12). The inhibitory ac-
tivities of these carbamates, as shown in Table 2,
reveal that the presence of an aromatic ring in the
substituent was not necessarily required for the activ-
ity, as demonstrated by the potent activities of the
N-
I-1
I-2
I-3
I-4
O
O
-
I-5
II-1
II-2
II-3
II-4
II-5
II-6
N
-
methyl and
N-isopropyl carbamates, III-8 and III-11.
In addition, the data for III-9, III-10 and III-12 seem
2.6
5.2
to show decreasing activity as the carbon number of
the
O-alkyl substituent was increased, although car-
bamate III-1 did not follow this trend.
*
#
Each carbamate was applied at a concentration of 1 m .
M
C: average length (cm) of coleoptiles. R: average length (cm) of the lon-
gest roots.
Finally, to verify the importance of the presence of
the sulfur atom in the
possessing an
N-substituent, carbamate IV
N
-2-phenylethyl group instead of N-
(phenylthio)methyl was prepared and compared with
III-2 for its inhibitory activity. As shown in Table 2,
carbamate IV had a much lower inhibitory eŠect on
oat germination, which means that the presence of a
Table 2, carbamate III-1 containing an
O-phenyl
functionality instead of the -2-pheylethyl in III-3
O
also had potent inhibitory activity. The introduction
of electron-withdrawing chlorine atoms to the phenyl
substituent (III-5) had no eŠect on the activity of
III-1. On the other hand, the distance between the
carbamoyl moiety and the phenyl group seemed to be
important, since carbamate III-4 having three methy-
lene units between the two functionalities had lower
inhibitory activity, while the activity was maintained
in the case of III-2 having one methylene unit. The
introduction of an electron-donating methoxy func-
tionality to the phenyl group of III-2 resulted in low-
er activity (III-6). The activity of III-4 was somewhat
improved by introducing a double bond (III-7) to the
three-methylene chain, which would have resulted in
some shortening of the chain. This result, as well as
sulfur atom in the
factor for the activity.
Sulfur-containing herbicides of the carbamate type
such as benthiocarb -4-chlorobenzyl diethyl-
thiocarbamate) and molinate ( -ethyl hexahydro-
-azepine-1-carbothioate) are now widely used in
N-substituent was an important
(
S
S
1
H
agricultural production. However, to the best of our
knowledge, the newly prepared carbamates contain-
ing an
N-(phenylthio)methyl substituent are un-
precedented in respect of the basic skeleton for a pes-
ticide, although the synthesis of III-9 and III-12 has
already been reported in the literature without any
comment on their biological activity.8)

424
B. H. ALIZADEH et al.
give 0.39 g (80
z
) of I-3 as crystals (mp 152–154
9
C);
Experimental
1
IR nmax (ˆlm) cm„1: 3350 (N–H), 1720 (C O); H-
＝
IR spectra were measured with a Jasco IR Report-
100 spectrometer. H-NMR spectra were recorded
NMR d: 3.80 (3H, s, CH3), 6.81 (1H, br s, NH),
1
6.87–6.09 (2H, m), 7.21–7.26 (3H, m), 7.35–7.42
(4H, m). Basically the same procedure was used for
the preparation of carbamates I and II, except that
commercially available isocyanates were employed
directly for I-1, I-4, I-5, and II-1–II-6.
with a Varian Gemini 2000 (300 MHz) spectrometer
in CDCl3, with tetramethylsilane used as an internal
standard. Mass spectra were recorded with a Jeol
JMS-700 spectrometer, and Merck silica gel 60
(70–230 mesh) was used for column chromato-
graphy.
Method B (exempliˆed by the preparation of
benzyl
N-( phenylthio)methylcarbamate
III-2).
Biological test. The biological test was carried out
DPPA (3.59 g, 13.1 mmol) and triethylamine (1.32 g,
13.1 mmol) were added to a solution of (phenylthio)
acetic acid (2.00 g, 11.9 mmol) in toluene (20 ml).
The mixture was stirred overnight at room tempera-
ture, washed with water, dried over MgSO4 and con-
centrated in vacuo to give 2.20 g (quantitative) of
(phenylthio)acetyl azide. To a stirred solution of
(phenylthio)acetyl azide (0.200 g, 1.04 mmol) in
toluene (5 ml) was added benzyl alcohol (0.110 g,
1.04 mmol) and triethylamine (5 drops), and the mix-
ture was stirred overnight at re‰uxing temperature
under a nitrogen atmosphere. The mixture was then
concentrated in vacuo, and the residue was dissolved
in ether. The ethereal solution was successively
according to the procedure described by Motando
2)
et al
(1
.
A solution of a carbamate sample in acetone
, 1 ml) was put on ˆlter paper in a sterilized
m
M
Petri dish (4 cm in diameter). After evaporating the
solvent, water (1 ml) was added. Four oat seeds
(
Avena sativa L. var. Zenshin) were rinsed with sodi-
um hypochlorite, placed on the ˆlter paper, and kept
in the dark at 25 C. After 6 days, the lengths of the
9
coleoptiles and the longest roots were measured.
Each experiment was conducted twice. As a control,
four oat seeds were put on ˆlter paper that had been
moistened only with 1 ml of water in the Petri dish,
and kept under the same conditions as those for the
test.
washed with 10
z
hydrochloric acid, sat. aq.
NaHCO3 and brine, dried over MgSO4 and concen-
trated in vacuo. The residue was chromatographed
over silica gel (40 g; hexane-ethyl acetate, 6:1) to give
General procedure for preparation of the carba-
mate derivatives.
Method A (exempliˆed by the preparation of
phenyl N-( p-methoxyphenyl)carbamate I-3). To a
0.11 g (37
z
) of III-2 as an oil, IR nmax (ˆlm) cm„1
:
1
＝
3320 (N–H), 1700 (C O); H-NMR
d
: 4.65 (2H, d,
＝
6.3 Hz, SCH2), 5.09 (2H, s, CH2), 5.18 (1H, br s,
stirred solution of
p
-methoxybenzoic acid (2.00 g,
J
13.1 mmol) in toluene (30 ml) was added dropwise
thionyl chloride (2.46 g, 20.6 mmol). The mixture
was heated at re‰uxing temperature for 30 min and
then concentrated in vacuo. The resulting acyl
chloride was dissolved in toluene (20 ml), and active
sodium azide4) (1.53 g, 23.6 mmol) was added to the
solution. The mixture was stirred for 24 h at room
temperature under a nitrogen atmosphere and then
ˆltered. The ˆltrate was washed with brine, dried
over MgSO4 and concentrated in vacuo. The residue
containing the corresponding acyl azide (IR, nmax
2140 cm„1) was dissolved in toluene (20 ml). After
being stirred for 2 h at re‰uxing temperature, the
mixture was concentrated in vacuo to give 1.57 g
NH), 7.23–7.40 (8H, m), 7.41–7.48 (2H, m); EIMS
m z: 274, 273 (M+), 219, 164, 154 (base peak), 149,
W
137, 136, 107, 91, 69, 57; HREIMS m z (M+):
W
found, 273.0823; calcd. for C15H15NO2S, 273.0823.
Basically the same method was used for the prepara-
tion of carbamates III and IV. The physical proper-
ties of the new carbamates were as follows: Phenyl
N
-(phenylthio)methylcarbamate (III-1): IR
n
max (ˆlm)
1
＝
3310 (N–H), 1730 (C O); H-NMR
d
: 4.71 (2H, d,
＝
J
5.8 Hz, SCH2), 5.39 (1H, br s, NH), 7.04–7.07
(2H, m), 7.15–7.23 (1H, m), 7.27–7.40 (5H, m),
7.48–7.56 (2H, m); EIMS m z: 259, 205, 185, 165
W
(base peak), 150, 137, 123, 110, 109, 107, 94, 77, 65,
56; HREIMS m z (M+): found, 259.0660; calcd.
W
(80
z
) of
p
-methoxyphenyl isocyanate (IR, nmax
for C14H13NO2S, 259.0667. 2-Phenylethyl
N-
2260 cm„1). The isocyanate obtained (0.30 g,
2.01 mmol) was dissolved in THF (10 ml), and
phenol (0.13 g, 1.34 mmol) and triethylamine
(5 drops) were added to the solution. The mixture
(phenylthio)methylcarbamate (III-3): IR nmax (ˆlm)
cm„1: 3310 (N–H), 1710 (C O); H-NMR
d
: 2.88
1
＝
＝
＝
(2H, t,
OCH2), 4.62 (2H, d,
s, NH), 7.16–7.23 (2H, m), 7.25–7.28 (3H, m),
J
6.7 Hz, PhCH2), 4.27 (2H, t,
J
6.7 Hz,
＝
J
6.6 Hz, SCH2), 5.03 (1H, br
was stirred for 2 h at 0–59C and then overnight at
room temperature. The mixture was concentrated in
vacuo, and the resulting residue was diluted with
ether. The ethereal solution was successively washed
7.29–7.34 (3H, m), 7.41–7.46 (2H, m); EIMS m z
:
W
287, 178, 123, 110, 105 (base peak), 104, 91, 77, 69,
65, 57; HREIMS m z (M+): found, 287.0985; calcd.
W
with 10
brine, dried over MgSO4 and concentrated in vacuo
The residue was crystallized from ether-hexane to
z
hydrochloric acid, sat. aq. NaHCO3 and
for C16H17NO2S, 287.0980. 3-Phenylpropyl
N
-
.
(phenylthio)methylcarbamate (III-4): IR nmax (ˆlm)
1
cm„1: 3310 (N–H), 1720 (C
＝
O); H-NMR d: 1.91

Preparation and Activity of
N
-Substituted Carbamates
425
＝
＝
＝
6.7 Hz, CH2CH3), 4.00 (2H, t, J 6.7 Hz, OCH2),
(2H, qui,
J
ca. 7.1 Hz, CH2), 2.66 (2H, t,
J
＝
＝
6.3 Hz, SCH2), 5.04 (1H, br s, NH),
7.6 Hz, CH2), 4.09 (2H, t,
J
6.5 Hz, CH2), 4.65
4.62 (2H, d,
J
＝
(2H, d,
J
6.6 Hz, SCH2), 5.11 (1H, br s, NH),
7.23–7.35 (3H, m), 7.43–7.47 (2H, m); EIMS m z
:
W
7.16–7.24 (3H, m), 7.24–7.38 (5H, m), 7.44–7.50
225 (base peak), 205, 168, 123, 116, 110, 109, 84, 77;
(2H, m); EIMS m z: 302, 301 (M+), 300, 192 (base
HREIMS m z (M+): found, 225.0825; calcd. for
W
W
peak), 154, 119, 91, 69, 55; HREIMS m z (M+):
C11H15NO2S, 225.0824. Isopropyl
N
-(phenylthio)
W
found, 301.1134; calcd. for C17H19NO2S, 301.1131.
methylcarbamate (III-11): IR nmax (ˆlm) cm„1: 3310
(N–H), 1700 (C O); H-NMR
1
＝
＝
2,4-Dichlorophenyl
N
-(phenylthio)methylcarbamate
d
: 1.19 (6H, d,
J
C; IR nmax (KBr) cm„1: 3320
6.3 Hz, CH(C
H
3)2), 4.62 (2H, d,
J
6.0 Hz, SCH2),
＝
(III-5): mp 76–77
9
1
(N–H), 1730 (C
＝
O); H-NMR
d
: 4.71 (2H, d,
J
J
＝
＝
4.89, (1H, sep,
J
＝
6.3 Hz, CH), 4.96 (1H, br s, NH),
6.3 Hz, SCH2), 5.53 (1H, br s, NH), 7.08 (1H, d,
7.28–7.36 (3H, m), 7.42–7.49 (2H, m); EIMS m z
:
W
226, 225 (M+), 145, 138, 123, 116 (base peak), 111,
＝
8.5 Hz), 7.21–7.26 (1H, dd,
J
8.5, 2.5 Hz),
95, 81, 69, 55; HREIMS m z (M+): found, 225.0822;
＝
7.32–7.40 (3H, m), 7.42 (1H, d,
J
2.5 Hz),
W
7.50–7.56 (2H, m); EIMS m z: 332, 331 (M+ for
calcd. for C11H15NO2S, 225.0821.
W
C14H1137Cl2NO2S), 330, 329 (M+ for C14H1137Cl35-
ClNO2S), 328, 327 (M+ for C14H1135Cl2NO2S), 289,
218, 165, 155, 154 (base peak), 138, 137, 136, 123,
Acknowledgment
120, 107, 89, 77, 57; HREIMS m z (M+): found,
We are grateful to Ms. T. Yamada (Tohoku
University) for measuring the mass spectra.
W
326.9890; calcd. for C14H1135Cl2NO2S, 326.9892.
p
-Methoxybenzyl
N
-(phenylthio)methylcarbamate
(III-6): IR nmax (ˆlm) cm„1: 3320 (N–H), 1700 (C
＝
＝
J
References
O); 1H-NMR
d
: 3.80 (3H, s, OCH3), 4.62 (2H, d,
1) Tomlin, C. D. S., ed., The Pesticide Manual, 11th Ed.,
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2) Matondo, H., Benevides, N., Tissut, M., Bergon, M.,
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thesis, mechanism of action, and herbicidal activity of
6.0 Hz, SCH2), 5.01 (2H, s, CH2), 5.09 (1H, br s,
＝
8.2 Hz), 7.23–7.36 (5H,
NH), 6.85–6.88 (2H, d,
J
m), 7.39–7.43 (2H, d, J 8.2 Hz); EIMS m z: 303
＝
W
(M+), 279, 256, 230, 167, 149, 137, 121 (base peak),
109, 91, 77, 57, 55; HREIMS m z (M+): found,
W
new aryl and alkyl
N-(4-pyridyl)carbamates. J. Agric.
303.0930; calcd. for C16H17NO3S, 303.0930. 3-
Food Chem., 37, 169–172 (1989).
Phenyl-2-propenyl
N-(phenylthio)methylcarbamate
3) Allen, C. F. H. and Bell, A., Undecyl isocyanate. In
``Organic Syntheses,'' Coll. Vol. 3, ed. Horning, E.
C., John Wiley & Sons, New York, pp. 846–847
(1955).
(III-7): IR nmax (ˆlm) cm„1: 3310 (N–H), 1700 (C
＝
O); 1H-NMR
d
: 4.66 (2H, d,
J
6.6 Hz, OCH2), 4.72
＝
＝
J
(2H, d,
J
6.0 Hz, SCH2), 5.18 (1H, br s, NH), 6.24
15.9, 6.6 Hz, C CHPh), 6.62 (1H, d,
4) Smith, P. A. S., The Curtius reaction. In ``Organic
Reactions,'' Vol. 3, ed. Adams, R., John Wiley &
Sons, New York, pp. 337–449 (1946).
(1H, dt,
＝
H
＝
＝
＝
15.9 Hz, CHPh), 7.25–7.41 (8H, m), 7.44–7.50
J
(2H, m); EIMS m z: 300, 299 (M+), 154, 136, 117
W
5) Overman, L. E., Taylor, G. F., Petty, C. B., and
(base peak), 91, 81, 69, 55; HREIMS m z (M+):
W
Jessup, P. J., trans-1-N-Acylamino-1,3-dienes:
found, 199.0982; calcd. for C17H17NO2S, 199.0984.
preparation from dienoic acids. J. Org. Chem., 43,
2164–2167 (1978).
Methyl
N
-(phenylthio)methylcarbamate (III-8): IR
1
＝
nmax (ˆlm) 3320 (N–H), 1720 (C O); H-NMR
d:
6) Shioiri, T., Ninomiya, K., and Yamada, S., Diphenyl-
phosphoryl azide. A new convenient reagent for a mo-
diˆed Curtius reaction and for peptide synthesis. J.
Am. Chem. Soc., 94, 6203–6205 (1972).
7) Rigby, J. H., Vinyl isocyanates as useful building
blocks for alkaloid synthesis. Synlett, 1–12 (2000).
3.66 (3H, s, CH3), 4.62 (2H, d, J 6.3 Hz, SCH2),
＝
5.10 (1H, br s, NH), 7.21–7.39 (3H, m), 7.43–7.46
(2H, m); EIMS m z: 197, 123, 110, 109, 88 (base
W
peak), 77, 65, 59; HREIMS m z (M+): found,
W
197.0514; calcd. for C9H11NO2S, 197.0510. Propyl
8) Bo
-arylmercapto-alkylisocyanates. Arch. Pharm., 302,
335–339 (0969).
ä hme, H. and Pasche, W., a-Alkylmercapto- and
N
-(phenylthio)methylcarbamate (III-10): IR nmax
(ˆlm) cm„1: 3340 (N–H), 1720 (C O); H-NMR
d
:
1
a
＝
＝
＝
7.4,
0.90 (3H, t,
J
7.4 Hz, CH3), 1.58 (2H, d t,
J