Synthesis of 5-Imino-1,2,4-oxadiazolidin-3-one

Article abstract of DOI:10.1081/SCC-120002523

N-Aryl-N-cyanocarbamoyl chloride and N-aryl-N-carbomethoxy-cyanamide were reacted with N-alkylhydroxyl-amines to afford selectively 2-alkyl-4-aryl-5-imino-1,2,4-oxazolidin-3-one and 2-alkyl-4-aryl-3-imino-1,2,4-oxadiazolidin-5-one, respectively.

Full text of DOI:10.1081/SCC-120002523

This article was downloaded by: [University of Colorado - Health Science Library]
On: 17 November 2014, At: 04:59
Publisher: Taylor & Francis
Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer
House, 37-41 Mortimer Street, London W1T 3JH, UK
Synthetic Communications: An International Journal
for Rapid Communication of Synthetic Organic
Chemistry
Publication details, including instructions for authors and subscription information:
http://www.tandfonline.com/loi/lsyc20
SYNTHESIS OF 5-IMINO-1,2,4-OXADIAZOLIDIN-3-ONE
Ge Hyeong Lee a , Hyo Won Lee b & Chwang Siek Pak a
a Korea Research Institute of Chemical Technology , P.O. Box 107, Yusung, Taejeon,
305-600, Korea
b Department of Chemistry , Chungbuk National University , Cheongju, Chungbuk,
360-763, Korea
Published online: 16 Aug 2006.
To cite this article: Ge Hyeong Lee , Hyo Won Lee & Chwang Siek Pak (2002) SYNTHESIS OF 5-IMINO-1,2,4-
OXADIAZOLIDIN-3-ONE, Synthetic Communications: An International Journal for Rapid Communication of Synthetic Organic
Chemistry, 32:5, 803-812, DOI: 10.1081/SCC-120002523
To link to this article: http://dx.doi.org/10.1081/SCC-120002523
PLEASE SCROLL DOWN FOR ARTICLE
Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained
in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no
representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of
the Content. Any opinions and views expressed in this publication are the opinions and views of the authors,
and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied
upon and should be independently verified with primary sources of information. Taylor and Francis shall
not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other
liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or
arising out of the use of the Content.
This article may be used for research, teaching, and private study purposes. Any substantial or systematic
reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any
form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http://
www.tandfonline.com/page/terms-and-conditions

SYNTHETIC COMMUNICATIONS, 32(5), 803–812 (2002)
SYNTHESIS OF 5-IMINO-
1,2,4-OXADIAZOLIDIN-3-ONE
Ge Hyeong Lee,1 Hyo Won Lee,2 and
Chwang Siek Pak1,
*
1Korea Research Institute of Chemical Technology,
P.O. Box 107, Yusung, Taejeon 305-600, Korea
2Chungbuk National University, Department of
Chemistry, Cheongju, Chungbuk 360-763, Korea
ABSTRACT
N-Aryl-N-cyanocarbamoyl chloride and N-aryl-N-carbo-
methoxy-cyanamide were reacted with N-alkylhydroxyl-
amines to afford selectively 2-alkyl-4-aryl-5-imino-1,2,
4-oxazolidin-3-one and 2-alkyl-4-aryl-3-imino-1,2,4-oxadi-
azolidin-5-one, respectively.
Those compounds with frameworks of 1,2,4-oxadiazolidine or its ana-
logues have diverse biological activities.1 For example, 1,2,4-oxadiazolidine-
3,5-dione, embodies the backbone of herbicides such as methazole and
BAS-3820. Relating to the structural modification of 1,2,4-oxadiazolidine-
3,5-dione, the carbonyl group at C-3 or C-5 can be modified to an imino group.
Several methods on the syntheses of 3-alkyl- (or aryl) imino-1,2,4-oxadiazo-
lidin-5-one have been reported.2–5 Nonetheless, the synthesis of 1,2,4-oxa-
diazolidin-5-one with free imino at 3-position has not yet been disclosed.
*Corresponding author.
803
Copyright & 2002 by Marcel Dekker, Inc.
www.dekker.com

ORDER
REPRINTS
804
LEE, LEE, AND PAK
We report herein the first synthesis of 5-imino-1,2,4-oxadiazolidin-3-
ones as well as 3-imino-1,2,4-oxadiazolidin-5-ones. In our initial synthetic
plan for the synthesis of 5-imino-1,2,4-oxadiazolidin-3-ones, carbodiimide
was excluded as a starting material utilizing 1,3-dipolar cycloaddition,
because it cannot produce the free imino group and besides, it is rather
difficult to prepare unsymmetrical carbodiimides. Careful examination of
structure of the desired product infers to the reaction routes shown in the
Scheme 1. Cleavage at the bond-a of the product discloses the construction
of framework from the cyclization reaction of N-cyanourea which can
be built upon N-hydroxy-N-alkyl-N0-arylurea (path a). Alternatively, the
cleavage at the bond-b of the product indicates the synthesis of the product
from the N-cyano-N-arylcarbamoyl chloride (path b) or its equivalent, i.e.,
an ester of N-cyano-N-arylcarbamate (path c).
Scheme 1.
The reaction of aniline and cyanogen bromide generated in situ in an
aqueous solution provided N-phenylcyanamide as a semihydrate, which was
subjected to the treatment with excess of phosgene to obtain N-cyano-N-
phenylcarbamoyl chloride (1a).6 Subsequent reaction of this carbamoyl
chloride with N-methylhydroxylamine in anhydrous acetonitrile in the pres-
ence of organic base such as triethylamine or pyridine led to a mixture of
desired product (6a) and its isomers (7a). However, the reaction of this

ORDER
REPRINTS
5-IMINO-1,2,4-OXADIAZOLIDIN-3-ONE
805
carbamoyl chloride (1a) with N-isopropylhydroxylamine7,8 in anhydrous
methanol in the presence of inorganic base such as sodium bicarbonate at
low temperature gave selectively the desired 5-imino-2-isopropyl-4-phenyl-
1,2,4-oxadiazolidin-3-one (6e) in almost quantitative yield (Scheme 2). The
synthetic methodology employing the inorganic base circumvented the
generation of the isomeric product and seems to be usually applicable to
prepare 2-alkyl-4-aryl-5-imino-1,2,4-oxadiazolidin-3-ones (6a–h).
Scheme 2.
As a supplementary route to the previous reaction of carbamoyl deriv-
atives, from the reaction of N-phenylcyanamide semihydrate with methyl
chloroformate, N-carbomethoxy-N-phenylcyanamide (2a) was obtained.
When this compound was allowed to react with equimolar amount of
N-isopropyl-hydroxylamine in refluxing ether, a mixture of the desired prod-
uct (6e) and its isomeric product (7f ) in the ratio of 54 : 46 was obtained. As it
was the case of 5-imino-1,2,4-oxadiazolidin-3-one, we hoped that the use of
inorganic base would differentiate the reactivities between N-cyano group
and carbamate group. Indeed, the utilization of sodium bicarbonate furn-
ished solely the isomeric product (7f ) in 72% yield. The structure of
this isomer was determined as 3-imino-1,2,4-oxadiazolidin-5-one deduced
from the spectroscopic data. A fragmental pattern of its mass spectrum show-
ing the expulsion of carbon dioxide from the molecular ion implied the pres-
ence of cyclic carbamate. 1H NMR spectrum of the isomeric product showed
a singlet at d 10.1 ppm, which is analogous to that of the guanidine, indicative
of the presence of 3-imino group, while characteristic 5-imino group of
the desired product at d 6.07 ppm was comparable to that of the imino
ester. The absorption peak of infrared spectroscopic data showed the
difference between 3-imino-1,2,4-oxadiazolidin-5-one (7) and 5-imino-1,2,4-
oxadiazolidin-3-one (6). Compound 6 showed C¼O stretching frequency at
1786 cmÀ1 and C¼N stretching frequency for the above isomer at 1668 cmÀ1
,
whereas 7 showed absorptions at 1738 and 1625 cmÀ1 for C¼O and C¼N

ORDER
REPRINTS
806
LEE, LEE, AND PAK
stretchings, respectively. Especially, the feature revealing marked difference
between C¼N stretchings for the above isomer was found to be consistent for
other analogous compounds we prepared. This process allowed easy access to
ortho-substituted 5-imino-1,2,4-oxadiazolidin-3-one (6). Judging from the
experimental evidence in the presence of inorganic base the reactivity
toward nucleophilic agents decreases in the order of carbamoyl>
N-cyanide>carbamate. According to substrates, carbamoyl chloride (1) or
carbomethoxycyanamide (2), and the reaction condition, 5-imino-1,2,4-oxa-
diazolidin-3-one (6) and 3-imino-1,2,4-oxadiazolidin-5-one (7) could be
obtained as a sole product. The results are summarized in Table 1.
After the successful synthesis of 3-imino and 5-imino-1,2,4-oxazolidin-
5(3)-ones with unsubstituted phenyl group, we undertook the preparation
of ortho-substituted phenyl derivatives from the reaction of N-ortho-
substituted phenyl-N-carbomethoxycyanamide (2) and N-alkylhydroxyl-
amine. However, in contrast to the N-alkylhydroxylamines, we could only
obtain the reaction intermediates of 2-hydroxyguanidine from the reaction
of N-aryl-N-carbomethoxycyanamide with hydroxylamine hydrochloride.
These intermediates were found to be defying the cyclization conditions.
It seems that this difficulty is originated from the steric hindrance caused
by the ortho substituents.
In addition to 2-alkyl substituted derivatives, we employed
o-protected hydroxylamine in other to provide the free form at 2-position
of 4-aryl-5-imino-1,2,4-oxadiazolidin-3-one. In the course of our synthesis,
hydroxylamine was protected as ethoxyethyloxyamine and was allowed to
react with carbamoyl chloride. The resulting reaction intermediate was
simultaneously deprotected and eventually cyclized to the desired product
under the acidic condition as shown in Scheme 3. This reaction was found
to be achievable so far only ortho-methyl derivative perhaps because of
acid lability of ethoxyethyloxy group in general and unexpected explosive
nature of the reaction.
Scheme 3.
It is noteworthy that there are existing discrepancy between our phy-
sical and spectral data for 5-imino-2-methyl-4-phenyl-1,2,4-oxadiazolidin-
3-one (6a) and 3-imino-2-methyl-4-phenyl-1,2,4-oxadiazolidin-5-one (7a)

ORDER
REPRINTS
5-IMINO-1,2,4-OXADIAZOLIDIN-3-ONE
807
Table 1. Reaction of N-Cyano-N-arylcarbamoyl Chloride (1a–d) and N-Aryl-N-
carbomethoxycyanamide (2a–e) with N-Alkylhydroxylamine (5)

ORDER
REPRINTS
808
LEE, LEE, AND PAK
and those reported previously in the literature. It seems that our
structural assignment is correct because of our consistency in the synthesis.
EXPERIMENTAL SECTION
General: Melting points were measured in open capillary tubes and
are uncorrected. 1H and 13C NMR spectra were recorded at 300 MHz,
unless otherwise specified, in CDCl3 solution using tetramethylsilane as
internal standard. Analytical thin-layer chromatography was performed
on precoated silica gel plates (0.25-mm 60 F-254 E. Merck). THF was
dried over sodium benzophenone prior to use.
General procedure for 2-alkyl-4-aryl-5-imino-1,2,4-oxadiazolidin-3-one
(6a–h): A slurry of N-alkyl or hydroxylamine hydrochloride (5.0 mmol),
anhydrous NaHCO3 (30.0 mmol) in dry methanol (20 ml) was stirred for
20 min at room temperature and then the temperature was lowered to
À78ꢀC. N-Cyano-N-arylcarbamoyl chloride (1) (5.0 mmol) in THF (5 ml)
was added dropwise for 10 min. The stirring was continued for 30 min at
À78ꢀC and the reaction temperature was allowed to rise slowly to room
temperature and the reaction mixture was stirred for 1.5 h. The reaction
mixture was combined with EtOAc (100 ml), washed with saturated brine,
and dried over MgSO4. After evaporation of solvent under the reduced
pressure, the residue was column chromatographied on silica gel by eluting
with CH2Cl2/EtOAc (3/1) to afford 6 as white solids.
2-Methyl-4-phenyl-5-imino-1,2,4-oxadiazolidin-3-one (6a): Yield 98%;
m.p. 102.5–103ꢀC; H NMR (300 MHz) d 7.30 (br, s, 5H, Ph), 5.80 (br, s,
1
1H, NH), 3.20 (s, 3H, CH3); IR (KBr) 3232 (NH), 1756 (CO), 1681
(C¼N) cmÀ1; MS m/e (rel. intensity) 192 (Mþ þ 1, 19.0), 191 (Mþ, 10.5),
134 (100), 118 (53.1), 91 (98.5), 90 (87.1), 64 (57.5). Anal. Calcd for
C9H9N3O2: C, 56.54; H, 4.75; N, 21.98. Found: C, 56.61; H, 4.73; N, 22.01.
2-Methyl-4-(2-methylphenyl)-5-imino-1,2,4-oxadiazolidin-3-one
(6b):
Yield 98%; m.p. 84.5–85ꢀC; H NMR (300 MHz) d 7.00–7.50 (m, 4H, aro-
matic), 5.60 (br, s, 1H, NH), 3.22 (s, 3H, CH3), 2.17 (s, 3H, CH3); IR (KBr)
3313 (NH), 1771 (CO), 1700 (C¼N) cmÀ1; MS m/e (rel. intensity) 205 (Mþ,
10.6), 160 (42.2), 104 (100), 78 (45.2). Anal. Calcd for C10H11N3O2: C, 58.53;
H, 5.40; N, 20.48. Found: C, 58.59; H, 5.28; N, 20.50.
1
2-Methyl-4-(2-methoxyphenyl)-5-imino-1,2,4-oxadiazolidin-3-one (6c):
Yield 98%; m.p. 135–136ꢀC; H NMR (300 MHz) d 6.80–7.60 (m, 4H, aro-
1
matic), 5.55 (br, s, 1H, NH), 3.77 (s, 3H, OCH3), 3.30 (s, 3H, CH3); IR
(KBr) 3291 (NH), 1760 (CO), 1694 (C¼N) cmÀ1; MS m/e (rel. intensity) 222
(Mþ þ 1, 11.2), 221 (Mþ, 56.1), 220 (36.5), 133 (61.1), 120 (100), 78 (48.8),

ORDER
REPRINTS
5-IMINO-1,2,4-OXADIAZOLIDIN-3-ONE
809
51 (52.7). Anal. Calcd for C10H11N3O3: C, 54.30; H, 5.01; N, 19.00. Found:
C, 54.41; H, 5.00; N, 19.08.
2-Methyl-4-(2-chlorophenyl)-5-imino-1,2,4-oxadiazolidin-3-one
(6d):
Yield 98%; 1H NMR (300 MHz) d 7.00–7.70 (m, 4H, aromatic), 5.95
(br, s, 1H, NH), 3.30 (s, 3H, CH3); IR (KBr) 3281 (NH), 1759 (CO), 1680
(C¼N) cmÀ1; MS m/e (rel. intensity) 226 (Mþ, 11.0), 190 (28.3), 120 (100),
78 (48.8), 51 (52.7). Anal. Calcd for C9H8ClN3O2: C, 47.91; H, 3.57; N,
18.62. Found: C, 47.89; H, 3.65; N, 18.65.
2-Isopropyl-4-phenyl-5-imino-1,2,4-oxadiazolidin-3-one (6e): Yield
93%; m.p. 64–64.5ꢀC; H NMR (300 MHz) d 7.40 (br, s, 5H, aromatic),
1
6.07 (br, s, 1H, NH), 4.20 (m, 1H, CH), 1.25 (d, J ¼ 6.0 Hz, 6H, 2CH3);
IR (KBr) 3302 (NH), 1786 (CO), 1668 (C¼N) cmÀ1; MS m/e (rel. intensity)
220 (Mþ þ 1, 32.2), 219 (Mþ, 7.1), 175 (97.5), 91 (40.2), 77 (40.3), 43 (100),
41 (54.3). Anal. Calcd for C11H13N3O2: C, 60.26; H, 5.98; N, 19.17. Found:
C, 60.23; H, 6.05; N, 19.18.
2-Isopropyl-4-(2-methylphenyl)-5-imino-1,2,4-oxadiazolidin-3-one (6f ):
Yield 94%; m.p. 64–64.5ꢀC; H NMR (300 MHz) d 6.90–7.50 (m, 4H, aro-
1
matic), 5.71 (br, s, 1H, NH), 4.20 (m, 1H, CH), 2.22 (s, 3H, CH3), 1.35
(d, J ¼ 6.0 Hz, 6H, 2CH3); IR (KBr) 3298 (NH), 1788 (CO), 1669
(C¼N) cmÀ1; MS m/e (rel. intensity) 234 (Mþ þ 1, 7.2), 233 (Mþ, 12.5),
146 (100), 104 (44.6), 43 (47.0). Anal. Calcd for C12H15N3O2: C, 61.79; H,
6.48; N, 18.01. Found: C, 61.69; H, 6.49; N, 17.96.
2-Isopropyl-4-(2-methylphenyl)-5-imino-1,2,4-oxadiazolidin-3-one (6g):
Yield 95%; m.p. 88.5–89ꢀC; 1H NMR (300 MHz) d 6.80–7.70 (m, 4H,
aromatic), 5.70 (br, s, 1H, NH), 4.25 (m, 1H, CH), 3.77 (s, 3H, OCH3),
1.35 (d, J ¼ 6.0 Hz, 6H, 2CH3); IR (KBr) 3297 (NH), 1784 (CO), 1674
(C¼N) cmÀ1; MS m/e (rel. intensity) 250 (Mþ þ 1, 29.1), 249 (Mþ, 12.5),
218 (39.2), 149 (53.4), 120 (71.3), 78 (38.1), 43 (100), 41 (61.6). Anal. Calcd
for C12H15N3O3: C, 57.82; H, 6.07; N, 16.86. Found: C, 57.89; H, 6.04; N,
16.79.
2-Isopropyl-4-(2-chlorophenyl)-5-imino-1,2,4-oxadiazolidin-3-one (6h):
Yield 97%; m.p. 82–83ꢀC; H NMR (300 MHz) d 7.20–7.70 (m, 4H, aro-
1
matic), 5.85 (br, s, 1H, NH), 4.20 (m, 1H, CH), 1.42 (d, J ¼ 6.0 Hz, 6H,
2CH3); IR (KBr) 3297 (NH), 1785 (CO), 1670 (C¼N) cmÀ1; MS m/e (rel.
intensity) 254 (Mþ, 22.6), 253 (17.9), 211 (55.5), 210 (44.1), 132 (32.9), 43
(100), 41 (54.1). Anal. Calcd for C11H12ClN3O2: C, 52.08; H, 4.77; N, 16.56.
Found: C, 52.21; H, 4.76; N, 16.60.
General procedure for 2-alkyl-4-aryl-3-imino-1,2,4-oxadiazolidin-5-
one (7a–k): A mixture of N-carbomethoxy-N-arylcyanamide (5.0 mmol),
N-alkyl or hydroxylamine hydrochloride (5.0 mmol), and anhydrous
NaHCO3 (20.0 mmol) in dry THF (20 ml) was stirred 1.5 h at room tem-
perature under nitrogen atmosphere. The insoluble solids were filtered off

ORDER
REPRINTS
810
LEE, LEE, AND PAK
and the filtrate was concentrated under the reduced pressure to afford crude
product, which was purified on the silica gel column eluted with
CH2Cl2/THF (10/1) to furnish the product as white solids. For analytical
sample, the product was recrystallized from isopropyl alcohol.
3-Imino-2-methyl-4-phenyl-1,2,4-oxadiazolidin-5-one (7a): Yield 75%:
m.p. 205–205.5ꢀC; H NMR (300 MHz) d 9.50 (br, s, 1H, NH), 680–7.50
1
(m, 5H, aromatic), 3.35 (s, 3H, NCH3); IR (KBr) 3141 (NH), 1773 (CO),
1615 (C¼N) cmÀ1; MS m/e (rel. intensity) 191 (Mþ, 23.5), 165 (45.5), 146
(100), 98 (60.0). Anal. Calcd for C9H9N3O2: C, 56.54; H, 4.74; N, 21.98.
Found: C, 56.41; H, 4.80; N, 21.91.
3-Imino-2-methyl-4-(2-methylphenyl)-1,2,4-oxadiazolidin-5-one
(7b):
Yield 58%: m.p. 144.5–145ꢀC; 1H NMR (300 MHz) d 9.30 (br, s, 1H,
NH), 6.80–7.50 (m, 4H, aromatic), 3.35 (s, 3H, NCH3), 2.20 (s, 3H, CH3);
IR (KBr) 3151 (NH), 1774 (CO), 1611 (C¼N) cmÀ1; MS m/e (rel. intensity)
205 (Mþ, 53.8), 162 (24.5), 159 (100), 118 (66.7). Anal. Calcd for
C10H11N3O2: C, 58.53; H, 5.40; N, 20.48. Found: C, 58.51; H, 5.49; N, 20.55.
3-Imino-2-methyl-4-(2-methoxyphenyl)-1,2,4-oxadiazolidin-5-one (7c):
Yield 72%: m.p. 119.5–120ꢀC; H NMR (300 MHz) d 9.00 (br, s, 1H, NH),
1
6.50–7.90 (m, 4H, aromatic), 3.71 (s, 3H, OCH3), 3.37 (s, 3H, NCH3); IR
(KBr) 3247 (NH), 1723 (CO), 1604 (C ¼ N) cmÀ1; MS m/e (rel. intensity) 222
(Mþ þ 1, 20.6), 221 (Mþ, 97.7), 175 (100), 56 (88.1). Anal. Calcd for
C10H11N3O3: C, 54.30; H, 5.01; N, 19.00. Found: C, 54.38; H, 5.02; N, 18.91.
3-Imino-2-methyl-4-(2-chlorophenyl)-1,2,4-oxadiazolidin-5-one
(7d):
Yield 58%: m.p. 144–144.4ꢀC; 1H NMR (300 MHz) d 9.25 (br, s, 1H,
NH), 6.85–7.75 (m, 4H, aromatic), 3.49 (s, 3H, NCH3); IR (KBr) 3205
(NH), 1730 (CO), 1598 (C¼N) cmÀ1; MS m/e (rel. intensity) 227 (Mþ þ 1,
14.7), 226 (Mþ, 23.9), 179 (100), 83 (80.1). Anal. Calcd for C9H8ClN3O2: C,
47.91; H, 3.57; N, 18.62. Found: C, 48.01; H, 3.56; N, 18.65.
3-Imino-2-methyl-4-(2-nitrophenyl)-1,2,4-oxadiazolidin-5-one
(7e):
Yield 92%: m.p. 153.5–154.5ꢀC; H NMR (300 MHz) d 10.1 (br, s, 1H,
NH), 7.10–8.20 (m, 4H, aromatic), 3.47 (s, 3H, NCH3); IR (KBr) 3198
(NH), 1776 (CO), 1603 (C¼N) cmÀ1. Anal. Calcd for C9H8N4O4: C,
45.77; H, 3.41; N, 23.72. Found: C, 45.88; H, 3.40; N, 23.64.
1
2-Isopropyl-3-imino-4-phenyl-1,2,4-oxadiazolidin-5-one(7f ):Yield72%:
m.p. 137.5–138.5ꢀC; 1H NMR (300 MHz) d 10.01 (br, s, 1H, NH), 6.80–7.77
(m, 4H, aromatic), 4.48 (m, 1H, CH), 1.20 (d, J ¼ 7.0 Hz, 6H, 2CH3); IR
(KBr) 3247 (NH), 1738 (CO), 1625 (C¼N) cmÀ1; MS m/e (rel. intensity)
220 (Mþ þ 1, 35.6), 219 (Mþ, 41.1), 145 (100), 77 (62.2). Anal. Calcd
for C11H13N3O2: C, 60.26; H, 5.98; N, 19.17. Found: C, 60.44; H, 5.96;
N, 19.15.
2-Isopropyl-3-imino-4-(2-methylphenyl)-1,2,4-oxadiazolidin-5-one (7g):
Yield 86%: m.p. 174–175ꢀC; H NMR (300 MHz) d 9.60 (br, s, 1H, NH),
1

ORDER
REPRINTS
5-IMINO-1,2,4-OXADIAZOLIDIN-3-ONE
811
6.90–7.30 (m, 4H, aromatic), 4.31 (m, 1H, CH), 2.20 (s, 3H, CH3), 1.18 (d,
J ¼ 6.0 Hz, 6H, 2CH3); IR (KBr) 3160 (NH), 1768 (CO), 1610 (C¼N) cmÀ1
;
MS m/e (rel. intensity) 234 (Mþ, 24.4), 146 (100), 118 (48.3). Anal. Calcd for
C12H15N3O2: C, 61.79; H, 6.48; N, 18.01. Found: C, 61.85; H, 6.50; N, 17.96.
2-Isopropyl-3-imino-4-(2-methoxyphenyl)-1,2,4-oxadiazolidin-5-one
(7h): Yield 80%: m.p. 172–173ꢀC; H NMR (300 MHz) d 9.60 (br, s, 1H,
1
NH), 6.60–7.60 (m, 4H, aromatic), 4.37 (m, 1H, CH), 3.74 (s, 3H, OCH3),
1.20 (d, J ¼ 6.0 Hz, 6H, 2CH3); IR (KBr) 3152 (NH), 1771 (CO), 1613
(C¼N) cmÀ1; MS m/e (rel. intensity) 250 (Mþ þ 1, 50.4), 249 (Mþ, 61.1),
175 (100), 56 (55.9). Anal. Calcd for C12H15N3O3: C, 57.82; H, 6.07; N,
16.86. Found: C, 57.89; H, 6.05; N, 16.80.
2-Isopropyl-3-imino-4-(2-chlorophenyl)-1,2,4-oxadiazolidin-5-one (7i):
Yield 78%: m.p. 157.5–158.5ꢀC; H NMR (300 MHz) d 9.90 (br, s, 1H,
1
NH), 6.90–7.70 (m, 4H, aromatic), 4.41 (m, 1H, CH), 1.24 (d, J ¼ 7.0 Hz,
6H, 2CH3); IR (KBr) 3178 (NH), 1736 (CO), 1602 (C¼ N) cmÀ1; MS m/e
(rel. intensity) 255 (Mþ þ 1, 19.8), 254 (Mþ, 35.7), 179 (94.4), 43 (100). Anal.
Calcd for C11H12ClN3O2: C, 52.08; H, 4.77; N, 16.56. Found: C, 52.11; H,
4.71; N, 16.63.
2-Isopropyl-3-imino-4-(2-nitrophenyl)-1,2,4-oxadiazolidin-5-one
(7j):
Yield 87%: m.p. 160–161ꢀC; 1H NMR (300 MHz) d 10.35 (br, s, 1H,
NH), 7.00–8.30 (m, 4H, aromatic), 4.47 (m, 1H, CH), 1.38 (d, J ¼ 7.0 Hz,
6H, 2CH3); IR (KBr) 3262 (NH), 1759 (CO), 1593 (C¼N) cmÀ1; MS m/e
(rel. intensity) 265 (Mþ þ 1, 13.1), 264 (Mþ, 10.0), 70 (100), 43 (44.8). Anal.
Calcd for C11H12N4O4: C, 50.00; H, 4.58; N, 21.20. Found: C, 49.90; H,
4.56; N, 21.19.
1
3-Imino-4-phenyl-1,2,4-oxadiazolidin-5-one (7k): Yield 93%; H NMR
(300 MHz) d 7.05–7.73 (m, 5H, Ph), 6.02 (br, s, 2H, 2NH); IR (KBr) 3347
(NH), 1748 (CO), 1638 (C ¼ N) cmÀ1; MS m/e (rel. intensity) 178 (Mþ þ 1,
50.2), 177 (Mþ, 80.2), 91 (64.3), 77 (100), 64 (40.0). Anal. Calcd for
C8H7N3O2: C, 54.24; H, 3.98; N, 23.72. Found: C, 54.41; H, 4.01; N, 54.32.
ACKNOWLEDGMENT
We thank the Ministry of Science and Technology for financial
support.
REFERENCES
1. Chemie der Pflanzenschutz und Schadlingsbekampfungsmittel, Wegler,
¨
R., Ed.; Springer-Vaerlag: Berlin, Heidelberg, 1977; Band V.
¨

ORDER
REPRINTS
812
LEE, LEE, AND PAK
2. Neitzel, M.; Zinner, G. Arch. Pharm. 1981, 314, 10.
3. Schecker, H.G.; Zinner, G. Arch. Pharm. 1981, 314, 268.
4. Zinner, G.; Gross, H. Chem. Ber. 1972, 105, 1709.
5. Voss, G.; Fischer, E.; Werchan, H.Z. Chem. 1973, 13, 102.
6. The presence of water in the N-phenylcyanamide precluded the conven-
tional method utilizing equimolar amount of phosgene with appropriate
bases or bubbling of phosgene in the presence of secondary amine.
7. Peter, A.S.S.; Husni, R.A.; Reuben, L.B. J. Am. Chem. Soc. 1964,
86, 1139.
8. Ryer, A.I.; Smith, G.B.L. J. Am. Chem. Soc. 1951, 73, 5675.
Received in Japan February 3, 2001

Request Permission or Order Reprints Instantly!
Interested in copying and sharing this article? In most cases, U.S. Copyright
Law requires that you get permission from the article’s rightsholder before
using copyrighted content.
All information and materials found in this article, including but not limited
to text, trademarks, patents, logos, graphics and images (the "Materials"), are
the copyrighted works and other forms of intellectual property of Marcel
Dekker, Inc., or its licensors. All rights not expressly granted are reserved.
Get permission to lawfully reproduce and distribute the Materials or order
reprints quickly and painlessly. Simply click on the "Request
Permission/Reprints Here" link below and follow the instructions. Visit the
U.S. Copyright Office for information on Fair Use limitations of U.S.
copyright law. Please refer to The Association of American Publishers’
(AAP) website for guidelines on Fair Use in the Classroom.
The Materials are for your personal use only and cannot be reformatted,
reposted, resold or distributed by electronic means or otherwise without
permission from Marcel Dekker, Inc. Marcel Dekker, Inc. grants you the
limited right to display the Materials only on your personal computer or
personal wireless device, and to copy and download single copies of such
Materials provided that any copyright, trademark or other notice appearing
on such Materials is also retained by, displayed, copied or downloaded as
part of the Materials and is not removed or obscured, and provided you do
not edit, modify, alter or enhance the Materials. Please refer to our Website
User Agreement for more details.
Order now!
Reprints of this article can also be ordered at
http://www.dekker.com/servlet/product/DOI/101081SCC120002523