A new method for the generation of α-nitrosoolefins from ketooximes and its application to the synthesis of 5,6-dihydro-4H-1,2-oxazine derivatives [1]

Article abstract of DOI:10.1002/jhet.5570420520

Reaction of ketooximes containing α-methylene group with chloramine-T followed by treatment with triethylamine leads to the formation of α-nitrosoolefins via α-nitrosochloride, which can react in situ intermolecularly with olefinic compounds to produce 5,

Full text of DOI:10.1002/jhet.5570420520

Jul-Aug 2005
877
A New Method for the Generation of α-Nitrosoolefins from
Ketooximes and its Application to the Synthesis of
5,6-Dihydro-4H-1,2-oxazine Derivatives [1]
S. L. Gaonkar and K. M. Lokanatha Rai*
Department of Studies in Chemistry, University of Mysore,
Manasagangotri, Mysore-570 006, India; e-mail: kmlrai@eth.net
Received December 17, 2004
Reaction of ketooximes containing α-methylene group with chloramine-T followed by treatment with tri-
ethylamine leads to the formation of α-nitrosoolefins via α-nitrosochloride, which can react in situ intermol-
ecularly with olefinic compounds to produce 5,6-dihydro-4H-1,2-oxazine derivatives in good yield.
J. Heterocyclic Chem., 42, 877 (2005).
the use of chloramine-T as a new efficient reagent for the
conversion of ketooxime bearing reactive methylene group
into α-nitrosochloride, which is suitable for in situ genera-
tion of α-nitrosoolefins during [4+2] cycloaddition to
olefins. Typically, the cycloaddition is carried out by
refluxing an equimolecular mixture of a ketooxime, chlo-
ramine-T trihydrate in ethanol followed by addition of tri-
ethylamine and an alkene in ethanol at rt. In general 5,6-
dihydro-4H-1,2-oxazine derivatives are thus obtained in
good yield .
[4+2] Cycloaddition of α-nitrosoolefins with olefinic
compounds are of synthetic interest since the product 5,6-
dihydro-4H-1,2-oxazines are versatile intermediates for
the synthesis of bifunctional compounds [2-4]. The
reduced product tetrahydro-4H-1,2-oxazines plays an
important role as partial structure in agricultural and horti-
cultural, fungicides, herbicides and broad spectrum of bac-
teriocides [5]. Compounds possessing the oxazine moiety
are also potential glycosidase inhibitors [6]. The usual
method of generating them is the elimination of hydrogen
halide from α-monohaloketooximes with triethylamine
[7]. However α-nitrosoolefins are highly reactive and
unstable, hence they are usually only generated in situ. The
yield of cycloaddition products often is low or side reac-
tions predominate, hence new procedure for the formation
of α-nitrosoolefins remain of interest.
Rai et al [8] extensively used chloramine-T for the
preparation of biologically active heterocycles via [3+2]
cycloaddition reaction of 1,3-dipolar species such as nitrile
oxides and nitrile imines with olefinic compounds. We
have successfully isolated the reactive intermediate nitrile
oxides by the oxidation of aldoximes with chloramine-T.
During the course of these studies, we have observed that
treatment of cyclohexanone oxime with chloramine-T pro-
duced a blue colour suggestive of formation of 1-chloro-1-
nitrosocyclohexane [6]. With this success, we now report
The reaction with chloramine-T proceeds with aromatic
as well as aliphatic ketooximes bearing α-hydrogen (e.g.
1a-f) and with styrene, acrylonitrile and with 1-methyl-
styrene.
The probable mechanism for the formation of α-nitroso-
olefins involves the interaction of ketoxime with chlo-
ramine-T to form α-nitrosochloride followed by the elimi-
nation of HCl in the presence of triethylamine (Scheme 2).
1
13
The structure proof is based on H nmr, C nmr, ms
studies and elemental analyses of the 5,6-dihydro-4H-1,2-
oxazine derivatives. As expected, the cycloaddition was
1
regioselective. H nmr indicated the presence of a single
1
isomer in all cases studied. All H nmr spectra of 5 (when
X=H), showed the signals due to C as a doublet of doublet
6
in the region 4.5-5.5 δ ppm while in 5 (when X=CH )
3
shows no signal in the said region and those due to C pro-
5
Scheme
1
1
R’
Ph
4
X
Z
a
b
c
d
e
f
a
b
c
H
H
Me
Ph
CN
Ph
p-Cl-C H -
p-NO -C H -
Isobutyl
Ethyl
Furyl
6
4
2
6 4

878
S. L. Gaonkar and K. M. L. Rai
Vol. 42
Scheme 2
The known compounds were identified by the comparison
of the spectral data with those described in the literature [9].
tons a multiplet in the region δ 1.9−2.5 ppm and those due
to C as a triplet in the region δ 2.0−2.8 ppm.
4
13
In the C nmr spectra, all oxazines gave consistent
signals for the newly formed ring carbons. For instance,
EXPERIMENTAL
the signals due to C appears in 5 (when X=H) as dou-
6
blet in the region δ 70−80 ppm while 5 (when X=CH )
Melting points were determined on Thomas Hoover melting
point apparatus and are uncorrected. H NMR spectra were
3
1
appears as singlet in the region δ 70−80 ppm and those
due to C and C appears as triplets in the region δ 15−
recorded on a Bruker AM 300 MHz spectrometer using CDCl as
3
5
4
13
solvent and tetramethylsilane as internal standard. C NMR
25 ppm and δ 25−30 ppm repectively. All oxazines
spectra were measured on Jeol 400 (100 MHz) instrument. The
chemical shifts are expressed in δ and following abbreviations
were used: s=singlet, d=doublet, t=triplet and m=multiplet. Mass
spectra were obtained on a Finnigan 4021 mass spectrometer at
an ionizing energy of 35 eV. Elemental analyses were obtained
on a Vario-EL instrument. Thin layer chromatography (TLC) was
done with pre-coated silica gel G plates using chloroform-ace-
tone (8:2) as eluent.
+
show MH as base peak and stable molecular ion peak
with relative abundance ranging from 7-20%. The for-
mation of the products was further supported by correct
elemental analyses.
3,6-Diphenyl-5,6-dihydro-4H-1,2-oxazine (5a).
Typical Procedure.
A mixture of 0.50 g (3.7 mmoles) of 1a and 1.05 g (3.73
mmoles) of chloramine-T trihydrate in ethanol (20 ml) were
refluxed for 2 hour. The mixture was cooled to room tempera-
ture, triethylamine (1 ml) was added and stirred at room tempera-
ture for 15 minutes. After this, solution of 0.39 g (3.75 mmoles)
of 4a in ethanol (5 ml) was added and stirred for 1 hour. It was
then concentrated under reduced pressure and the residue is
In summary we have demonstrated for the first time that
oxazines can be easily synthesized by the reaction of
ketooximes bearing α-methylene group with alkenes in
presence of chloramine-T and triethylamine in almost 60-
83% yield.
extracted with CH Cl (25 ml). This extract was then washed
2
2
with water (15 ml), with 1 N aq. NaOH (2 × 15 ml) and dried
(Na SO ). The solvent was evaporated and the remaining pale
2
4
yellow solid was recrystallized from alcohol-n-hexane to gave 5a

Jul-Aug 2005
A New Method for the Generation of α-Nitrosoolefins from Ketooximes
879
as a creamy white crystalline solid, yield 0.630 g (72%), mp 159-
This compound was obtained from 0.50 g (2.94 mmol) of 1b,
0.44 g (3.7 mmol) of 4c, 0.84 g (2.95 mmol) of chloramine-T tri-
hydrate and triethylamine as a pale yellow oil to yield 0.550 g
1
161 °C (lit. mp 160-162 °C) [9]; H nmr (deuteriochloroform): δ
2.18 (m, 2H, CH ), 2.73 (t, 2H, CH ), 4.82 (dd, 1H, J=10.3Hz &
2
2
1
2.7Hz, CH), 7.35-7.50 (m, 8H, ArH), 7.72-7.78 (m, 2H, ArH).
Anal. Calcd. for C NO: C, 80.98; H, 6.37; N, 5.90.
(65%); H nmr (deuteriochloroform): δ 1.41 (S, 3H, CH ), 1.98
3
H
(t, 2H, CH ), 2.73 (t, 2H, CH ), 7.28-7.37 (m, 5H, ArH), 7.51
16 15
2
2
13
Found: C, 80.93; H, 6.44; N, 5.84.
The same procedure was used in all cases.
(dd, 2H, ArH), 7.68 (dd, 2H, ArH); C nmr (deuteriochloro-
form): δ 24.6 (q), 27.0 (t), 28.1 (t), 80..4 (s), 123.7 (d), 128.0 (d),
128.6 (d), 129.4 (d), 129.9 (d), 131.2 (s), 137.1 (s), 139.2 (s),
164.1(s); ms m/z: 286 (MH , 100), 285 (M ,11), 151 (15), 137
(11), 134 (8), 120 (18), 77 (40).
3-Phenyl-5,6-dihydro-4H-1,2-oxazine-6-carbonitrile (5b).
+
+
This compound was obtained from 0.50 g (3.7 mmoles) of 1a,
0.2 g (3.76 mmol) of 4b, 1.05 g (3.73 mmoles) of chloramine-T
trihydrate and triethylamine as a pale yellow crystalline solid,
Anal. Calcd. for C
H ClNO: C, 71.45; H, 5.64; N, 4.90.
17 16
Found: C, 71.48; H, 5.67; N, 4.88.
1
yield 0.550 g (80%), mp 100-102 °C; H nmr (deuteriochloro-
3-(4-Nitrophenyl)-6-phenyl-5,6-dihydro-4H-1,2-oxazine (5g).
form): δ 2.08 (m, 2H, CH ), 2.72 (t, 2H, CH ), 5.14 (dd, 1H,
2
2
13
J=9.6 & 2.4Hz, CH), 7.30-7.50 (m, 5H, ArH); C nmr (deuteri-
ochloroform): δ 15.1 (t), 27.4 (t), 72.10 (d), 119.6 (s), 128.9 (d),
129.2 (d), 130.6 (d), 132.1 (s), 165.1 (s); ms m/z: 187 (MH+,
100), 186 (M+,6), 117 (10), 103 (13).
This compound was obtained from 0.50 g (2.77 mmol) of 1c,
0.29 g (2.78 mmol) of 4a, 0.79 g (2.81 mmol) of chloramine-T
trihydrate and triethylamine as a yellow crystalline solid to yield
1
0.587 g (75%), mp 186-188 °C (lit mp 188-189 °C) [9]; H nmr
Anal. Calcd. for C
H N O: C, 70.95; H, 5.41; N, 15.04.
(deuteriochloroform): δ 2.16 (m, 2H, CH ) 2.74 (t, 2H, CH ),
11 10 2
2
2
Found: C, 70.98; H, 5.49; N, 15.01.
4.78 (dd, 1H, J=10.1 & 2.9Hz, CH), 7.31-7.42 (m, 5H ArH), 7.84
(dd, 2H, ArH ), 8.12 (dd, 2H, ArH).
6-Methyl-3,6-diphenyl-5,6-dihydro-4H-1,2-oxazine (5c).
Anal. Calcd. for C
H N O : C, 68.07; H, 5.0; N, 9.92.
16 14 2 3
This compound was obtained from 0.50 g (3.7 mmoles) of
1a, 0.44 g (3.70 mmol) of 4c, 1.05 g (3.73 mmoles) of chlo-
ramine-T trihydrate and triethylamine as a off white crystalline
solid, yield 0.620 g (67%), mp 128-130°C (lit mp 128-129°C)
Found: C, 68.09; H, 4.98; N, 9.94.
3-(4-Nitrophenyl)-5,6-dihydro-4H-1,2-oxazine-6-carbonitrile
(5h).
1
[9]; H nmr (deuteriochloroform): δ 1.59 (s, 3H, CH ), 2.12 (t,
3
This compound was obtained from 0.50 g (2.77 mmol) of 1c,
0.15 g (2.83 mmol) 4b, 0.15 g (2.83 mmol), 0.79 g (2.81 mmol)
of chloramine-T trihydrate and triethylamine as a yellow oil to
2H, CH ), 2.42 (t, 2H, CH ), 7.17-7.35 (m, 8H, ArH), 7.60-7.76
2
2
(m, 2H, ArH).
Anal. Calcd. for C
H NO: C, 81.24; H, 6.82; N, 5.57.
17 17
1
yield 0.532 g (83%); H nmr (deuteriochloroform): δ 2.07 (m,
Found: C, 81.22; H, 6.85; N, 5.59.
2H, CH ), 2.73 (t, 2H, CH ), 4.89 (dd, 1H, J=9.4 & 2.6 Hz, CH),
2
2
13
7.93 (dd, 2H ArH), 8.13 (dd, 2H, ArH); C nmr (deuteriochloro-
3-(4-Chlorophenyl)-6-phenyl-5,6-dihydro-4H-1,2-oxazine (5d).
form): δ 16.2 (t), 28.6 (t), 71.5 (d), 119.6 (s), 123.1 (d), 128.6 (d),
This compound was obtained from 0.50 g (2.94 mmol) of 1b,
0.31 g (2.98mmol) of 4a, 0.84 g (2.95 mmol) of chloramine-T tri-
hydrate and triethylamine as a pale yellow oil, yield 0.560 g
+
+
139.2 (s), 151.4 (s), 162.6 (s); ms m/z: 232 (MH , 100), 231 (M ,
8), 162 (14), 148 (02).
Anal. Calcd. for C H N O : C, 57.14; H, 3.92; N, 18.17.
11
9 3 3
1
(70%); H nmr (deuteriochloroform): δ 2.02 (m, 2H, CH ), 2.66
2
Found: C, 57.19; H, 3.90; N, 18.16.
(t, 2H, CH ), 4.48 (dd, 1H, J=10.3 & 2.4Hz, CH), 7.20-7.35 (m,
5H, ArH), 7.45 (dd, 2H, ArH), 7.65 (dd, 2H, ArH); C nmr
2
13
6-Methyl-3-(4-nitro-phenyl)-6-phenyl-5,6-dihydro-4H-1,2-
oxazine (5i).
(deuteriochloroform): δ 22.2 (t), 29.6 (t), 80.2 (d), 125.4 (d),
128.4 (d), 128.6 (d), 129 (d),129.6 (s), 130.8 (d), 134.2 (s), 138.2
This compound was obtained from 0.50 g (2.77 mmol) of 1c,
0.33 g (2.78 mmol) 4c, 0.79 g (2.81 mmol) of chloramine-T tri-
hydrate and triethylamine as a pale yellow crystalline solid to
+
+
(s), 164.1 (s); ms m/z: 272 (MH , 100), 271 (M , 8), 151 (20),
137 (10), 120 (17), 106 (4), 77 (38).
Anal. Calcd. for C
H ClNO: C, 70.72; H, 5.19; N, 5.15.
1
16 14
yield 0.575 g (70%), mp 167-169 °C (lit mp 168-172 °C) [9]; H
Found: C, 70.70; H, 5.22; N, 5.17.
nmr (deuteriochloroform): δ 1.45 (s, 3H, CH ), 1.98 (t, 2H, CH ),
3
2
2.19 (t, 2H, CH ), 7.37-7.5 (m, 5H, ArH), 7.73 (dd, 2H, ArH),
3-(4-Chlorophenyl)-5,6-dihydro-4H-1,2-oxazine-6-carbonitrile
(5e).
2
8.19 (dd, 2H, ArH).
Anal. Calcd. for C
H N O : C, 68.44; H, 6.08; N, 9.39.
17 16 2 3
Obtained from 0.50 g (2.94 mmol) of 1b, 0.20 g (3.76
mmol) of 4b, 0.84 g (2.95 mmol) of chloramine-T trihydrate
Found: C, 68.49; H, 6.06; N, 9.37.
1
and triethylamine as a pale yellow oil, yield 0.530 g (81%); H
3-Isobutyl-6-phenyl-5,6-dihydro-4H-1,2-oxazine (5j).
nmr (deuteriochloroform): δ 2.11 (m, 2H, CH ), 2.74 (t, 2H,
2
This compound was obtained from 0.50 g (4.34 mmol) of
1d, 0.46 g (4.35mmol) of 4a, chloramine-T (1.23 g, 4.37
mmol) and triethylamine as a yellow oil to yield 0.594 g
CH ), 5.22 (dd, 1H, J=10.1 & 2.9Hz, CH), 7.33 (d, 2H ArH),
2
13
7.62 (d, 2H, ArH ); C nmr (deuteriochloroform): δ 15.1 (t),
29.2 (t), 71.40 (d), 118.5 (s), 129.6 (d), 130 (s), 131.8 (d),
134.2 (s), 163.6 (s); ms m/z: 221 (MH , 100), 220 (M , 6),
151 (18), 137 (10).
1
(63%); H nmr (deuteriochloroform): δ 1.01 (s, 6H, CH ),
3
+
+
1.31-1.37 (m, 4H, CH ), 1.84 (m, 1H, CH), 2.02 (m, 2H,
2
CH ), 4.53 (dd, 1H, J=9.8 & 2.5 Hz, CH), 7.22-7.64 (m, 5H,
2
Anal. Calcd. for C H ClN O: C, 59.88; H, 4.11; N, 12.70.
11
9
2
13
ArH); C nmr (deuteriochloroform): δ 20.4 (d), 22.8 (q), 23.1
Found: C, 59.85; H, 4.15; N, 12.68.
(t), 28.5 (t), 43.1 (t), 80.2 (d), 124.8 (d), 127.9 (d), 128.5 (d)
+
3-(4-Chlorophenyl)-6-methyl-6-phenyl-5,6-dihydro-4H-1,2-
oxazine) (5f).
137.6 (s), 163.8(s); ms m/z: 218 (MH , 100), 120 (12), 106
(15), 97 (28), 83 (6), 77 (10).

880
S. L. Gaonkar and K. M. L. Rai
Vol. 42
Anal. Calcd. for C
Found: C, 77.32; H, 8.84; N, 6.44.
H
NO: C, 77.38; H, 8.81; N, 6.45.
7.9 (q), 24.2 (q), 26.2 (t), 27.0 (t), 27.1 (t), 80.6 (s), 126.1 (d),
14 19
+
128.4 (d), 128.9 (d), 139.9 (s), 165.0 (s); ms m/z: 204 (MH ,
+
100), 203(M , 6), 135 (8),120 (28), 77 (30), 69 (6), 55 (13).
3-Isobutyl-5,6-dihydro-4H-1,2-oxazine-6-carbonitrile (5k).
Anal. Calcd. for C
H NO: C, 76.81; H, 8.43; N, 6.89.
13 17
This compound was obtained from 0.50 g (4.34 mmol) of 1d,
0.24 g (4.52 mmol) of 4b, 1.23 g (4.37 mmol) of chloramine-T
trihydrate and triethylamine as a pale yellow oil to yield 0.490 g
Found: C, 76.75; H, 8.46; N, 6.93.
3-Furan-2-yl-6-phenyl-5,6-dihydro-4H-1,2-oxazine (5p).
1
This compound was obtained from 0.5 g (4.0 mmol) of 1f,
0.42 g (4.03 mmol) of 4a, 1.14 g (4.05 mmol) of chloramine-T
trihydrate and triethylamine as a yellow oil to yield 0.635 g
(69%); H nmr (deuteriochloroform): δ 1.05 (s, 6H, CH ), 1.29-
3
1,34 (m, 4H, CH ), 1.85 (m, 1H, CH), 2.07 (m, 2H, CH ), 4.33
2
2
13
(dd, 1H, J=9.9 & 2.5Hz CH); C nmr (deuteriochloroform): δ
18.2 (t), 20.4 (d), 23.4 (q), 27.1 (t), 44.2 (t), 71.4 (d), 119.2 (s),
164.1 (s); ms m/z: 167 (MH , 100), 97 (10), 83 (8).
1
(70%); H nmr (deuteriochloroform): δ 1.33 (t, 2H, CH ), 1.88
2
+
(m, 2H, CH ), 4.54 (dd, 1H, , J=9.2 & 2.3 Hz, CH), 6.32-6.37
2
13
(m, 2H, furyl), 7.20-7.30 (m, 5H, ArH), 7.43 (d, 1H, furyl);
C
Anal. Calcd. for C H N O: C, 65.03; H, 8.49; N, 16.85.
9
14 2
nmr (deuteriochloroform): δ 21.0 (t), 27.1 (t), 80.2 (d), 112.2
Found: C, 64.99; H, 8.52; N, 16.87.
(d), 125.1 (d), 128.8 (d), 129.1 (d) 137.8 (s), 140.2 (d), 141 (s),
3-Isobutyl-6-methyl-6-phenyl-5,6-dihydro-4H-1,2-oxazine (5l).
+
+
165.2 (s); ms m/z: 228 (MH , 100), 227 (M , 17), 107 (32),
93(38), 77 (21).
This compound was obtained from 0.50 g (4.34 mmol) of
1d, 0.52 g (4.40 mmol) of 4c, 1.23 g (4.37 mmol) of chlo-
ramine-T trihydrate and triethylamine as a pale yellow oil to
Anal. Calcd. for C
H NO : C, 73.99; H, 5.77; N, 6.16.
14 13 2
Found: C, 74.05; H, 5.74; N, 6.12.
1
yield 0.580 g (58%); H nmr (deuteriochloroform): δ 1.04 (s,
3- Furan-2-yl-5,6-dihydro-4H-1,2-oxazine-6-carbonitrile (5q).
6H, CH ), 1.33-1.39 (m, 4H, CH ), 1.51 (s, 3H, CH ), 1.89
3
2
3
13
This compound was obtained from 0.5 g (4.0 mmol) of 1f, 0.22
g (4.15 mmol) of 4b, 1.14 g (4.05 mmol) of chloramine-T trihy-
drate and triethylamine as a yellow oil to yield 0.549 g (78%); H
(m, 1H, CH), 1.99 (m, 2H, CH ), 7.30-7.40 (m, 5H, ArH);
C
2
nmr (deuteriochloroform): δ 20.9 (d), 23.0 (q), 25.8 (q), 26.4
1
(t), 27.8 (t), 43.2 (t), 80.3 (s), 124.8 (d), 127.9 (d), 128.2 (d),
+
nmr (deuteriochloroform): δ 1.32 (t, 2H, CH ), 1.87 (m, 2H, CH ),
137.1 (s), 163.5 (s); ms m/z: 232 (MH , 100), 134 (8), 120
2
2
4.23 (dd, 1H, J=9.6 & 2.4Hz, CH), 6.30-6.36 (m, 2H, furyl), 7.42
(25), 97 (2), 83 (7),77 (11).
13
(d, 1H, furyl); C nmr (deuteriochloroform): δ 15.1 (t), 29.0 (t),
Anal. Calcd. for C
H NO: C, 77.88; H, 9.15; N, 6.05.
15 21
72.1 (d), 112.0 (d), 119.3 (s), 140.2 (d) 143.2 (s), 163.5 (s); ms m/z:
Found: C, 77.81; H, 9.19; N, 6.07.
+
+
177 (MH , 100), 176(M , 20), 107 (29), 93 (38).
Anal. Calcd. for C H N O : C, 61.36; H, 4.58; N, 15.90.
3-ethyl-6-phenyl-5,6-dihydro-4H-1,2-oxazine (5m).
9
8 2 2
Found: C, 61.30; H, 4.60; N, 15.93.
This compound was obtained from 0.50 g (5.70 mmol) of 1e,
0.60 g (5.76 mmol) of 4a, 1.62 g (5.76 mmol) of chloramine-T
trihydrate and triethylamine as a pale yellow oil to yield 0.673 g
3-Furan-2-yl-6-methyl-6-phenyl-5,6-dihydro-4H-1,2-oxazine
(5r).
1
(63%); H nmr (deuteriochloroform): δ 1.07 (t, 3H, CH ), 1.33 (t,
3
This compound was obtained from 0.5 g (4.0 mmol) of 1f, 0.51
g (4.32 mmol) of 4c, 1.14 g (4.05 mmol) of chloramine-T trihy-
drate and triethylamine as a yellow oil to yield 0.616 g (64%);
2H, CH ), 1.44 (m, 2H, CH ), 2.02 (m, 2H CH ), 4.53 (dd, 1H,
2
2
2
13
J=10.2 & 2.8Hz, CH), 7.2-7.4 (m, 5H, ArH); C nmr (deuteri-
ochloroform): δ 7.5 (q), 23.9 (t), 26.9 (t), 27.5 (t), 81.1 (d), 125.4
1
+
H nmr (deuteriochloroform): δ 1.33 (t, 2H, CH ), 1.52 (s, 3H,
(d), 127.6 (d), 128.0 (d), 137.2 (s), 163.4 (s); ms m/z: 190 (MH ,
2
+
CH ), 1.93 (m, 2H, CH ), 6.30-6.36 (m, 2H, furyl), 7.19-7.28 (m,
5H, ArH), 7.42 (d, 1H, furyl); C nmr (deuteriochloroform): δ
24.2 (q), 25.7 (t), 26.7 (t), 79.8 (s), 112.1 (d), 125.1 (d),128.4 (d),
100), 189 (M , 7), 106 (20), 77 (30), 69 (6), 55 (10).
3
2
13
Anal. Calcd. for C
H NO: C, 76.16; H, 7.99; N, 7.40.
12 15
Found: C, 76.10; H, 8.03; N, 7.44.
+
128.8 (d), 139.4 (d), 142.1 (s), 163.9 (s); ms m/z: 242 (MH ,
3-Ethyl-5,6-dihydro-4H-1,2-oxazine-6-carbonitrile (5n).
+
100), 241 (M , 16), 120 (35), 107 (29),93 (32), 77 (25).
Anal. Calcd. for C
Found: C, 74.62; H, 6.30; N, 5.79.
H NO : C, 74.67; H, 6.27; N, 5.80.
This compound was obtained from 0.50 g (5.70 mmol) of 1e,
0.31 g (5.84 mmol) of 4b, 1.62 g (5.76 mmol) of chloramine-T tri-
15 15 2
hydrate and triethylamine as a pale yellow oil to yield 0.547 g
1
(69%); H nmr (deuteriochloroform): δ 1.06 (t, 3H, CH ), 1.33 (t,
3
REFERENCES AND NOTES
2H, CH ), 1.43 (m, 2H, CH ), 2.04 (m, 2H, CH ), 4.26 (dd, 1H,
2
2
2
13
J=9.9 & 2.6 Hz, CH), 7.23-7.40 (m, 5H, ArH); C nmr (deuteri-
ochloroform): δ 8.5 (q), 17.2 (t), 27.0 (t), 27.8 (t), 73.3 (d), 118.9 (s),
163.9 (s); ms m/z: 139 (MH , 100), 138 (M , 9) 69 (4), 55 (12) .
Anal. Calcd. for C H N O: C, 60.85; H, 7.30; N, 20.27.
Found: C, 60.80; H, 7.33; N, 20.30.
[1] For previous paper, see M. Suresh Babu and K. M. L. Rai,
Tetrahedron Lett., 45, 7969 (2004).
+
+
[2] G. Petros Tsoungas, Heterocycles, 57, 1149 (2002) and refer-
ences cited therein; G. Petros Tsoungas, Heterocycles, 57, 915 (2002) and
references cited therein; M. Naruse, S. Aoyagi, and C. Kibayashi,
Tetrahedron Lett., 35, 595 (1994) and references cited therein.
[3] T. L. Gilchrist, Chem. Soc. Rev., 12, 53 (1983) and references
cited therein.
7
10 2
3-Ethyl-6-methyl-6-phenyl-5,6-dihydro-4H-1,2-oxazine (5o).
This compound was obtained from 0.50 g (5.70 mmol) of 1e,
0.68 g (5.76 mmol) of 4c, 1.62 g (5.76 mmol) of chloramine-T
trihydrate and triethylamine as pale yellow oil to yield 0.653 g
[4]
cited therein.
[5] K. M. Patel and T. M. Stevenson, WO Patent 9 209 587 (1992);
G. W. Kirby, Chem. Soc. Rev., 6, 1 (1997) and references
1
(56%); H nmr (deuteriochloroform): δ 1.07 (t, 3H, CH ), 1.30 (t,
Chem. Abstr., 117, 131232 (1992); R. Zimmer, J. Arnold, K. Homann and
H. U. ReiBig, Synthesis, 1050 (1994) and references cited therein.
[6] A. Defoin, H. Sarazin, C. Strehler, and J. Streith, Terahedron
3
H, CH ), 1.43 (m, 2H, CH ), 1.59 (s, 3H, CH3), 1.99 (t, 2H,
2
2
13
CH2), 7.28-7.40 (m, 5H, ArH); C nmr (deuteriochloroform): δ

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A New Method for the Generation of α-Nitrosoolefins from Ketooximes
881
Lett., 35, 5653 (1994).
[8] A. Hassner and K. M. L. Rai, Synthesis, 57 (1989).
[7] T. L. Gilchrist and T. G. Roberts, J. Chem. Soc., Perkin Trans.
I, 1283 (1983).
[9] D. E. Davies, T. L. Gilchrist and T. G. Roberts, J. Chem. Soc.,
Perkin Trans. I, 1275 (1983).