Chemistry of diazocarbonyl compounds: XX. Chemoselective O-alkylation of 3(2H)-oxoisothiazole-1,1-dioxides

Article abstract of DOI:10.1023/B:RUJO.0000043724.25474.51

Catalytic decomposition of diazoacetylacetone, ethyl diazoacetate, and diethyl diazomalonate effected by dirhodium tetraacetate in the presence of 3(2H)-oxoisothiazole-1,1-dioxides resulted in O-alkylation of amide carbonyl of the heterocycle affording th

Full text of DOI:10.1023/B:RUJO.0000043724.25474.51

Russian Journal of Organic Chemistry, Vol. 40, No. 5, 2004, pp. 740-746. Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 5, 2004,
pp. 773-780.
Original Russian Text Copyright Ó 2004 by Schulze, Nikolaev, Hennig, Rodina, Sieler, Nikolaev.
.
To the dear memory of Professor I.K.Korobitsyna
Chemistry of Diazocarbonyl Compounds: XX.* Chemoselective
O-Alkylation of 3(2Í)-Oxoisothiazole-1,1-dioxides
with the Use of Rh(II)-Carbenoids
B. Schulze2, Vs.V. Nikolaev1, L. Hennig2, L.L. Rodina1, J. Sieler2, and V.A. Nikolaev1
1St. Petersburg State University, St. Petersburg, 198504 Russia
e-mail: vnikola@VN6646.spb.edu
..
..
2Universitat Leipzig, Institut fur Organische Chemie Johannisallee, 29, 04103, Leipzig, Germany
Received July 10, 2003
Abstract—Catalytic decomposition of diazoacetylacetone, ethyl diazoacetate, and diethyl diazomalonate
effected by dirhodium tetraacetate in the presence of 3(2H)-oxoisothiazole-1,1-dioxides resulted in
O-alkylation of amide carbonyl of the heterocycle affording the corresponding enol ethers in preparative
yield. The reaction occurred chemoselectively. The 1,3-dicarbonyl derivatives of 3-hydroxyisothiazole-
1,1-dioxides obtained in contrast to analogous N-alkylated products are not enolized in solutions and in
crystals.
rivatives [2, 3]. A similar trend was observed in the for-
merly described reactions of amides and lactams with
diketocarbenoids and other structurally related substances
[9].**
Within last 10–15 years the synthetic potential of
saccharine chemistry was considerably extended with
new procedures for functionalization and
transfunctionaliation of this heterocyclic system, for
expansion and opening of the ring, fusion of heterocycles,
for preparation of chiral derivatives of isothiazole-1,1-
dioxides, etc. [2–4]. Besides the compounds of this class
attract attention for they possess versatile biological
activity [2–4], and saccharin although its harmlessness
for human organism is dubious [5] still is widely used as
substitute for sugar. Therefore the study of reactivity
underlying development of new methods of
oxoisothiazole-1,1,-dioxides functionalization remains an
urgent task of organic chemistry.
In this connection we expected that the reaction of
carbenoids B with oxaisothiazole-1,1-dioxides A would
afford N-alkylated products C and thus we would be able
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We investigate of reactions of saccharine and its ana-
logs with metallocarbenes and other intermediates origi-
nating from diazo compounds [6]. A molecule of 3(2H)-
oxoisothiazole-1,1-dioxide A possesses several nucleophilic
groups, potential reaction sites for attack of carbenoids
B that have pronounced electrophilic character [7, 8]. It
was however presumable that intermediate B would re-
act first of all with the nitrogen of the heterocycle, for the
electrophilic reagents were known to react with saccha-
rins with a free N–H groups to give N-substituted de-
I, R, R' = (CH)4 (a), (CH2)4 (b), (CH2)5 (c); R = Ph, R' = Me (d);
R, R' = Me (a); R = Me, R' = O-i-Pr (b); R, R' = OFt (c); R,
R' = CH2C(Me2)CH2 (d); R, R' = OC(Me2)O (e); Ln = (OAc)n.
R1, R2 = (CH)4, R3 = R4 = Me (a); R1, R2 = (CH2)5, R3 = R4 =
Me (b); R1 = Ph, R2 = R3 = R4 = Me (c); R1, R2 = (CH)4, R3 =
Me, R4 = O-i-Pr (d); R1, R2 = (CH2)4, R3 = R4 = OEt (e); R1 =
Ph, R2 = Me, R3 = R4 = OEt (f).
** The term “diketocarbenoids” is used here as a general notation of
diacyl-, acyl(alkoxycarbonyl)-, and di(alkoxycarbonyl)carbenoids
with two carbonyls in the a,a'-position with respect to carbenoid
carbon.
* For communication XIX see [1].
1070-4280/04/4005-0740Ó2004 MAIK “Nauka/Interperiodica”

741
CHEMISTRY OF DIAZOCARBONYL COMPOUNDS: XX.
2
2
to develop a new procedure for functionalization of the
N–H bond of the substrate.
+
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5
2
We report here on results of catalytic decomposition
by rhodium tetraacetate of a series of diazodicarbonyl
compounds in the presence of saccharine and its ana-
logs. We selected as objects of investigation 3(2H)-oxo-
1,2-benzisothiazole-1,1-dioxide (Ia) (saccharine), its
hydrogenised analog 3(2H)-oxo-4,5,6,7-tetrahydro-1,2-
benzisothiazole-1,1-dioxide (Ib), 3(2H)-oxocyclohepta-
[d]isothiazole-1,1-dioxide (Ic), and also a monocyclic rep-
resentative of the isothiazoles series under study, 5-me-
thyl-4-phenyl-3(2H)-oxoisothiazole-1,1-dioxide (Id). Ex-
cept for saccharine (Ia) all other compounds were prepar-
ed by a three-stage procedure from the corresponding
ketones involving as the final stage isothiazoles oxidation
with hydrogen peroxide in the glacial acetic acid [10, 11].
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R1, R2 = (CH)4, R3 = R4 = Me (a); R1, R2 = (CH2)5, R3 =
R4 = Me (b); R1 = Ph, R2 = R3 = R4 = Me (c); R1, R2 = (CH)4,
R3 = Me, R4 = O-i-Pr (d); R1, R2 = (CH2)4, R3 = R4 = OEt (e);
R1 = Ph, R2 = Me, R3 = R4 = OEt (f).
yielded adducts of substrates I and carbenoid intermedi-
ates IIIa–c at a molar ratio 1:1. The thorough spectral
investigations (see further) showed that the compounds
obtained had a structure of enol ethers of oxoisothiazoles
IVa–f and not of expected N-alkylamides, i.e. formally
they are products of diketocarbenoids III insertion into
O–H bond of the enol form of 3(2H)-oxoisothiazoles I.
In order to elucidate the opportunities and limitations
of the process under investigation we used for generat-
ing diketocarbenoids III various acyclic and cyclic 2-
diazo-1,3-dicarbonyl compounds: diazoacetylacetone
(IIa), ethyl diazoacetoacetate (IIb), diethyl diazomalonate
(IIc), diazodimedone (IId), and its heterocyclic analog,
5-diazo-4,6-dioxo-2,2-dimethyl-1,3-dioxane (IIe).
Under conditions we developed for reactions of diazo
compounds IIa–c and subsequent separation of reaction
products ethers IV were obtained in preparative yields
1
(73–95%), and according H NMR spectra registered
just after completion of the reaction side products in sig-
nificant amounts were not detected.
Reaction with cyclic diazodicarbonyl compounds IId,
e under similar conditions obviously proceeded in differ-
ent way. At catalytic decomposition of diazodimedone
IId 5,5-dimethyl-2-chloro-1,3-cyclohexanedione (V) was
isolated in over 60% yield. It is presumable that in this
case the corresponding diacylcarbenoid IIId reacts mainly
with the solvent (CH2Cl2) giving rise to an intermediate
halogenonium ylide D that through a series of further
transformations affords finally 5,5-dimethyl-2-chloro-1,3-
cyclohexanedione (V).
I, R, R' = (CH)4 (a), (CH2)4 (b), (CH2)5 (c); R = Ph, R' = Me
(d).
The catalytic decomposition of diazo compounds IIa–
e in the presence of Rh2(OAc)4 was carried out in anhy-
drous dichloromethane or 1,2-dichloroethane at 15–20°C
or at elevated temperature; on reaction completion (TLC
monitoring) the reaction mixture was separated on a col-
umn packed with silica gel, and the isolated substances
were recrystallized.
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The catalytic reaction of oxoisothiazole-1,1-dioxides
The catalytic decomposition of heterocyclic analog of
Ia–d with acyclic diazodicarbonyl compounds IIa–c
diazodimedone (IId), 5-diazo-4,6-dioxo-2,2-dimethyl-1,3-
RUSSIAN JOURNALOF ORGANIC CHEMISTRY Vol. 40 No. 5 2004

742
SCHULZE et al.
IVa–d containing two or at least one acetyl group in the
molecular structure the molecular ion peaks were of a
very low intensity (1–5%), apparently due to their low
stability against electron impact and easy ejection of
acetyl cation (CH3C=O)+ or ketene molecule (CH2=C=O)
from these molecular ions. This is evidenced by appear-
ance in the mass spectra of compounds IVa–d of ions
having m/z 43 and maximal abundance (100%).
In general the first stages of molecular ions fragmen-
taion for ethers IVa–f involve successive degradation of
the side chain, namely, of the carbenoid fragment of the
molecule of these heterocyclic compounds with elimina-
tion of molecules C2H4, C3H7, CO, CH2C=O, H2O,
CH3CO2H etc. that is common for carboxylic acids es-
ters and 1,3-dicarbonyl compounds [12].
Another characteristic feature of fragmentation of
molecular and fragment ions of ethers IVa–f is interme-
diate formation under conditions of mass spectrum re-
cording of ions corresponding to initial sulfonamides Ia–
d that have taken up one hydrogen atom and possessing
even molecular masses of 184, 188, 202, and 224 re-
spectively. The successive fragmentation paths of these
ions are very similar to that of molecular ions of oxo-
isothiazole-1,1-dioxides Ia–d and their simplest 3-alkoxy
derivatives occurring under similar conditions[12, 13].
Molecular strusture of 3-(diacetylmethoxy)-5-methyl-4-
phenyl-1,2-isothiazole-1,1-dioxide molecule (IVc) according to
X-ray data
dioxane (IIe), in the presence of Rh2(OAc)4 under the
same conditions proceeded very slow.As shown by TLC
even after several days the reaction mixture contained
considerable amounts of initial reagents Ia and IIe. The
attempts to intensify the process by adding new portions
of the catalyst or by heating to 83°C (boiling in 1,2-di-
chloroethane) resulted in multicomponent mixtures of
products. We failed to isolate individual compounds from
the mixture.
In the IR spectrum of each obtained compound IVa–
–1
f usually in the region 1000–2000 cm a number of strong
absorption bands is observed of stretching vibrations of
–1
carbonyl [1718–1746 (C=O oxo) and 1762–1771 cm
–1
(C=O ester)], C=N group (1574–1650 cm ), and SO2
group (1361–1399 and 1164–1176 cm ). These absorp-
Inasmuch as published data on spectral characteris-
tics of O-alkylation products generated by treating imi-
des and amides with diketocarbenoids were lacking we
thoroughly studied ethers IVa–f by means of mass spec-
trometry, IR, 1H and 13C NMR spectroscopy. This part
of investigation was aimed at determination of charac-
teristic spectral parameters of enol O-ethers IV for mak-
ing it possible to use these characteristics for identifica-
tion of analogous compounds by spectral methods. Be-
sides an X-ray diffraction study was performed with ad-
duct IVc containing two acetyl substituents in the 1,3-di-
carbonyl fragment of the molecule. The main results of
the analytical part of the study are considered below.
–1
tion bands are consistent with the assumed structure of
compounds IV [2, 3, 11]. However the IR spectra of
these compounds do not contain unambiguous indications
of the existence of enol tautomers.
1H and 13C NMR spectra of adducts obtained contain
complete sets of proton and carbon signals correspond-
ing to the structures of enol ethers IVa–f. The signals
from the oxothiadiazole and diketocarbenoid fragments
of the molecule show that the adducts are formed in 1:1
ratio. The position of signals is in general close to the
corresponding parameters in the NMR spectra of initial
Ia–d and IIa–c. The main change in the spectra of com-
pounds IV compared to those of the initial reagents con-
sisted in appearance of a clear one-proton singlet from a
methine group [OCH(COR3)COR4] in the region 5.6–
6.0 ppm of the 1H NMR spectra and a strong signal from
the carbon atom of the same group in the region 76–
91 ppm of the 13C NMR spectra.
In the electron-impact mass spectra of all prepared
compounds IVa–f were observed molecular ion peaks
[M]+. (m/z: 281, 299, 321, 325, 345, 381 respectively),
therewith for ethers IVe, f containing two ethoxycarbonyl
groups in the carbenoid fragment of the molecule these
peaks were among the most abundant in the spectra (70
and 45% from the maximum). In the spectra of enol ethers
RUSSIAN JOURNALOF ORGANIC CHEMISTRY Vol. 40 No. 5 2004

743
CHEMISTRY OF DIAZOCARBONYL COMPOUNDS: XX.
The position of the methine carbon is strongly affected
by the character of substituents R3 and R4, same as is
observed for the position of the carbon from the CN2
groups in initial diazodicarbonyl compounds IIa–c. The
most downfield position (90–91 ppm) hold signals of car-
bon atoms from OCH group of adducts IVa–c with two
acyl substituents. On replacing one of these by an
alkoxycarbonyl group in compound IVd this signal shifted
to stronger field by 7.3–7.9 ppm (the signal was observed
at 82–83 ppm). Introducing one more alkoxycarbonyl
group into the molecules of adducts IVe, f resulted in still
further upfield shift of the OCH group signal by 6.5–7.5
ppm (to 76–77 ppm).
the O-alkylated products under consideration by spectral
methods.
Hence it can be concluded that the carbon signals
from the methine group (OCH) in the 13C NMR spectra
of enol ethers IV are located in a narrow region of spec-
trum characteristic of each definite type of substituents
R3 and R4. Therefore these signals can be a reliable
source of identification in reaction mixtures of products
of O-alkylation at the amide carbonyl group. It should be
also noted that the methine signals under discussion in
the 1H and 13C NMR spectra of compounds of IV type
are located in “free”, not overloaded with other reso-
nances spectral regions thus facilitating their efficient
application to a diagnostic task.
It should be pointed out that compounds IVa–d with
acyl groups in the 1,3-dicarbonyl fragment of the mol-
ecule are practically nonenolized in chloroform solution
(according to 1H and 13C NMR data ) and in the crystal-
line state (according to X-ray analysis). This fact distin-
guished these compounds from analogous N-alkyl de-
rivatives prepared from amides and lactames that exist
exclusively in enol form [8, 14]. This feature significantly
simplifies the identification in the reaction mixtures of
The molecular structure of one among the adducts,
3-(diacetylmethoxy)-5-methyl-4-phenyl-1,2-isothiazole-
1,1-dioxide (IVc), established by X-ray diffraction analy-
sis is presented on figure, the main geometric parameters
of molecule IVc are given in table. These data unam-
biguously testify in favor of the O-(alkyl)isothiazole struc-
ture of compounds obtained, and also confirm the lack of
enolization (in crystal) in arising from this reaction de-
rivatives IV of 1,3-dicarbonyl compounds.
Main structural parameters of 3-(diacetylmethoxy)-5-methyl-4-phenyl-1,2-isothiazole-1,1-dioxide molecule (IVc)
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RUSSIAN JOURNALOF ORGANIC CHEMISTRY Vol. 40 No. 5 2004

744
SCHULZE et al.
5ꢀ
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substrates containing O–H bond and for enolized carbonyl
compounds [7, 8, 17].
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The reaction of saccharin and its analogs that we have
discovered is a new process of O-alkylation with
metallocarbenes of amide carbonyl groups in oxoisothi-
azole-1,1-dioxides that provides a possibility in one stage
to introduce polycarbonyl substituents into the position 3
of the heterocyclis system and that nobody has investi-
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1H and 13C NMR spectra were registered on spec-
trometer Brucker 500 at operating frequencies 500 (1H)
and 126 MHz (13C) in CDCl3, internal reference TMS.
Mass spectra of compounds IVa–f were measured at
direct admission of samples into the ionization chamber,
ionizing electrons energy 70 eV. IR spectra were recorded
an spectrophotometer Specord 75IR from KBr pellets.
)
The formation mechanism of enol ethers IV that may
be formally regarded as carbenoid insertion products into
the O–H bond of the enol form of oxoisothiazole-1,1-
dioxides I apparently primarily involves an attack of elec-
trophilic diketocarbenoid III on the oxygen of a carbonyl
group affording intermediate carbonyl ylide E [15, 16].
The subsequent stabilization of ylide E giving enol ether
IV may occur either through a 1,4-sigmatropic shift of a
proton [16] of NH group or by migration of this proton to
the anionic site of the carbonylylide via enol intermedi-
ate F.
X-ray diffraction study was carried out on a colorless
single crystal of compound IVc, crystal habit 0.3 ´ 0.25 ´
0.3 mm, obtained by crystallization from a mixture
CH2Cl2–Et2O, ~1:2. Crystals of O-ether IVc tetragonal,
°
a 10.433(4), b 10.433(4), c 14.425(1) A, a = b = g = 90°,
°
V 1570.2(7) A3, Ccalc 1.359 g/cm3, space group P4(3).
The products of insertion into the O–H bond IVa–f
hardly can arise along “oxonium” pathway, i.e. involving
enol forms of cyclic sulfonimides I and then oxonium
ylides G.
The measurement was carried out at 293(2) K on a
diffractometer Siemens SMART CCD, using radiation
°
of wavelength 0.71073 A. Extinction factors were evalu-
ated by SADABS program, the processing of structural
data was performed by SHELXS97 software [18].
Spectral investigations of 3-oxobenzo-1,2-isothiazoles,
saccharin, and its analogs I show [2, 3, 11] that these
carbonyl compounds exist in solutions and in crystalline
state exclusively in the ketoamide form and contain no
enol tautomer. At the same time the presence of the latter
can be regarded as a necessary condition for proceeding
of the process under consideration through oxonium ylide
Saccharin (Ia) was prepared from commercial sac-
charine sodium salt, tetrahydrosaccharin Ib and
oxoisothiazoles Ic, d were synthesized by procedures [10,
11, 19]. Oxoisothiazoles Ia–d were additionally purified
by sublimation in a vacuum at 40°C (0.05 mm Hg). Melt-
ing points of sublimed compounds are as follows: 228–
229 (Ia), 135–136 (Ib), 116–117 (Ic), 183–184°C (Id).
Diazocarbonyl compounds IIa–e were synthesized
by diazotransfer [20, 21] and purified by distillation or
sublimation in a vacuum. Diazoacetylacetone (IIa), bp
29–30°C (0.1 mm Hg), nD20 1.5071. 13C NMR spectrum
(0.2 mol l-1), d, ppm: 191.5 (C=O), 82.5 (CN2), 26.6
(CH3). Ethyl diazoacetoacetate (IIb), bp 40–42°C (1.5
mm Hg), nD20 1.4725. 13C NMR spectrum (0.3 mol l-1),
d, ppm: 183.9 (C=O), 161.4 (C=O), 76.3 (CN2), 61.4
(CH2), 28.1 (COCH3), 14.3 (CH2CH3). Diethyl
diazomalonate (IIc), bp 44–45°C (0.1 mm Hg), nD20 1.4830.
13C NMR spectrum (0.2 mol l-1), d, ppm: 161.2 (C=O),
71.9 (CN2), 61.7 (CH2), 14.4 (CH3). 2-Diazo-5,5-dim-
ethyl-1,3-cyclohexanedione (IId), mp 107–108°C (subl.).
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*
RUSSIAN JOURNALOF ORGANIC CHEMISTRY Vol. 40 No. 5 2004

745
CHEMISTRY OF DIAZOCARBONYL COMPOUNDS: XX.
13C NMR spectrum (0.2 mol l-1), d, ppm: 189.6 (C=O),
83.05 (CN2), 50.5 (CH2), 31.0 (CMe2), 28.3 (CH3). 5-Di-
azo-2,2-dimethyl-1,3-dioxane-4,6-dione (IIe), mp 96–97°C
(subl.). 13C NMR spectrum (0.2 mol l-1), d, ppm: 158.5
(C=O), 107.0 (O–C–O), 65.4 (CN2), 26.6 (CH3).
1361, 1329, 1212, 1171, 1056. 13C NMR spectrum, d,
ppm: 27.8, 89.8 (OCH), 122.7, 123.9, 126.0, 134.2, 135.2,
144.1, 168.3, 197.0. Mass spectrum, m/z (Irel, %): 281
(1.4) [M]+., 264 (0.7), 239 (10.0), 222 (5.7), 217 (3.6),
184 (10.7), 175 (2.9), 166 (4.3), 146 (7.9), 133 (5.0), 103
(32.9), 76 (12.1), 51 (6.7), 43 (100). Found, %: C 51.43,
51.42; H 3.90, 3.91; N 4.93, 4.85; S 11.50, 11.23.
C12H11NO5S. Calculated, %: C 51.24; H 3.91; N 4.98;
S 11.38.
The reaction progress was monitored by TLC on
Silufol UV-254 plates, for column chromatography was
used neutral silica gel Chemapol L 40/100 or Merck (70–
230 mesh).
3-(Diacetylmethoxy)-4,5-pentamethylenisothi-
azole-1,1-dioxide (IVb). Colorless substance, yield 86%,
mp 159–160°C (from a mixture petroleum ether–
The procedure for catalytic decomposition of acyclic
diazodicarbonyl compounds IIa–c was published in [6].
Catalytic decomposition of 2-diazo-5,5-dimethyl-
1,3-cyclohexanedione (IId). To a solution of 0.42 g
(2.5 mmol) of diazodimedone IId in 20 ml of dichloro-
methane was added 0.37 g (2 mmol) of saccharine (Ia),
and at stirring and cooling to 0–5°C 10 mg of dirhodium
tetraacetate was charged to the reaction mixture. In 10–
15 min the cooling was removed, and the mixture was
stirred till the completion of reaction (TLC monitoring).
In the course of reaction saccharine (Ia) dissolved com-
pletely, the green color of the reaction mixture turned
brown, and the nitrogen evolution ceased. The mixture
was charged on to a small column packed with silica gel,
the gradient elution was performed with ethyl ether-pe-
troleum ether mixture. On removing solvents and recrys-
tallization of the main product from a mixture Et2O–
CH2Cl2, ~ 2:1, we obtained 0.27 g (61%) 5,5-dimethyl-
2-chloro-1,3-cyclohexanedione (V), mp 162–165°C
–1
CH2Cl2). IR spectrum, cm : 1746, 1718, 1640, 1564, 1447,
1
1379, 1321, 1216, 1164, 1074, 1108, 996. H NMR spec-
trum (0.3 mol l-1) d, ppm: 1.83–1.95 m (6H, 3 CH2), 2.33 s
(6H, 2 CH3), 2.68–2.62 m (4H, 2 CH2), 5.69 s (1H,
OCH). 13C NMR spectrum, d, ppm: 25.0, 25.5, 26.6,
26.8, 29.5, 27.6, 90.0 (OCH), 132.8, 157.3, 170.9, 196.8.
Mass spectrum, m/z (Irel, %): 299 (5.0) [M]+, 282 (1.4),
257 (14.3), 240 (3.6), 229 (2.5), 214 (2.1), 202 (5.7), 193
(6.4), 168 (5.0), 151 (7.1), 136 (6.4), 122 (7.9), 99 (7.9),
93 (15.0), 77 (11.4), 65 (10.0), 53 (7.1), 43 (100). Found,
%: C 52.49, 52.30; H 5.78, 5.68; N 4.53, 4.52; S 10.30,
10.64. C13H17NO5S. Calculated, %: C 52.17; H 5.68;
N 4.68; S 10.70.
3-(Diacetylmethoxy)-5-methyl-4-phenyl-
isothiazole-1,1-dioxide (IVc). Yield 73%, mp 154–
–1
155°C (from Et2O–CH2Cl2) [6]. IR spectrum, cm : 1724,
13
1
(subl.). H NMR spectrum (0.2 mol l-1, d, ppm: 1.11 s
1629, 1566, 1420, 1376, 1326, 1209, 1174, 1135. C NMR
spectrum, d, ppm: 10.7, 27.9, 90.6 (OCH), 126.9, 129.5,
129.7, 130.0, 130.9, 153.3, 170.6, 197.2. Mass spectrum,
m/z (Irel, %): 321 (4.6) [M]+, 306 (1.4), 279 (22.1), 257
(7.9), 250 (5.0), 236 (14.3), 224 (7.3), 215 (7.1), 198 (7.1),
186 (8.6), 173 (7.1), 156 (7.1), 144 (6.4), 130 (7.1), 115
(35.7), 99 (9.3), 89 (3.6), 77 (5.0), 63 (2.9), 51 (4.3), 43
(100). Found, %: C 56.11, 56.21; H 4.76, 4.75; N 4.28,
4.36; S 9.79, 9.53. C15H15NO5S. Calculated, %: C 56.07;
H 4.67; N 4.36; S 9.96.
(6H, 2CH2), 2.47 s (4H, 2CH2), 5.70 br.s (~ 1H, CHCl).
Catalytic decomposition of 5-diazo-2,2-dimethyl-
1,3-dioxane-4,6-dione (IIe) under similar conditions
(2.5 mmol of saccharin, 2.5 mmol of diazo compound, 10
mg of Rh2OAc4, CH2Cl2) proceeded exceedingly slow.
In two days at 18–20°C and after boiling in CH2Cl2 the
reaction mixture contained mainly initial compounds (TLC
data). At separation of the reaction mixture on silica gel
we recovered 0.34 g (79.5%) of diazodioxodioxane IIe
and 0.34 g (74%) of saccharin (Ia); we failed to isolate
any individual compounds from other fractions.
3-(Acetylisopropoxycarbonylmethoxy)-benzo[d]-
isothiazole-1,1-dioxide (IVd). Colorless oily substance,
–1
yield 76%. IR spectrum (KBr), cm : 1769, 1733, 1616,
The reaction carried out in 1,2-dichloroethane at 83°C
for 1 h with reagents and catalyst taken in the same
amounts afforded a multicomponent mixture (TLC data).
However the separation of the mixture on silica gel af-
forded as in the first run only the initial diazodioxodioxane
IIe and saccharin (Ia) in over 80% yield.
1
1567, 1461, 1393, 1337, 1253, 1173, 1100, 1063. H NMR
spectrum (0.3 mol l-1), d, ppm: 1.32 d, 1.35 d (6H, 2CH3,
J 6.2 Hz, ), 2.48 s (3H, CH3C=), 5.20 septet (1H,
OCHMe2, J 6.2 Hz, ), 5.90 s [1H, OCHAc (CO2-i-Pr)],
7.75–7.96 m (4H, arom). 13C NMR spectrum, d, ppm:
21.8, 21.6, 27.7, 71.9, 82.5(OCH), 122.3, 124.0, 133.8,
134.8, 125.8, 143.8, 162.3, 168.3, 194.9. Mass spectrum,
m/z (Irel, %): 325 (0.9) [M]+, 283 (1.6), 261 (3.6), 241
(2.1), 219 (3.0), 202 (2.1), 184 (28.6), 175 (4.6), 166 (4.3),
3-(Diacetylmethoxy)benzo[d]isothiazole-1,1-di-
oxide (IVa). Yield 86%, mp 166–168°C (from Et2O–
–1
CH2Cl2) [6]. IR spectrum, cm : 1720, 1614, 1554, 1401,
RUSSIAN JOURNALOF ORGANIC CHEMISTRY Vol. 40 No. 5 2004

746
SCHULZE et al.
of Carbenes, Kazan, 2003, p. 38.
144 (6.7), 118 (3.9), 103 (16.4), 102 (25.7), 84 (12.1), 76
(9.6), 55 (10.0), 43 (100).
7. Doyle, M.P., McKervey, M.A., andYe, T., Modern Catalytic
Methods for Organic Synthesis with Diazo Compounds,
New York: Wiley, 1998, 652 p.
3-(Diethoxycarbonylmethoxy)-4,5-tetramethyl-
enisothiazole-1,1-dioxide (IVe). Yield 95%, mp 59–
60°C (from a mixture petroleum ether–CH2Cl2) [6]. IR
8. Maas, G., Topics in Current Chemistry, 1987, vol. 137, p. 75;
Adams, J. and Spero, D.M., Tetrahedron, 1991, vol. 47,
p. 1765; Padwa, A. and Krumpe, K.E., Tetrahedron, 1992,
vol. 48, p. 5385; Shapiro, E.A., Dyatkin, A.B., and Nefe-
dov, O.M., Diazoefiry ( Diazoesters), Moscow: Nauka, 1992,
148 p; Khlebnikov,A.F., Novikov, M.S., and Kostikov, R.R.,
Adv. Heterocyclic Chem., 1996, vol. 65, p. 93; Kantin, G.P.
and Nikolaev, V.A., Sovrem. Probl. Org. Khimii, St. Peters-
burg: Izd. St. Peterburg. Gos. Univ., 1998, vol. 12, p. 132;
Davies, H.M.L., Hansen, T., and Churchill, M.R., J. Am.
Chem. Soc., 2000, vol. 122, p. 3063.
9. Cama, L.D. and Christensen, B.G., Tetrahedron Lett., 1978,
p. 4233; Ratcliffe, R.W., Salzmann, T.N., and Christen-
sen, B.G., Tetrahedron Lett., 1980, vol. 21, p. 31; Salz-
mann, T.N., Ratcliffe, R.W., Christensen, B.G., and Bouf-
fard, F.A., J. Am. Chem. Soc., 1980, vol. 102, p. 6161; Hry-
tsak, M. and Durst, T., Heterocycles, 1987, vol. 26, p. 2393;
Osipov, S.N., Sewald, N., Kolomiets,A.F., Fokin,A.V., and
Burger, K., Tetrahedron Lett., 1996, vol. 37, p. 615; Mlo-
ston, G., Celeda, M., Swiatek, A., Kagi, M., and Heimgart-
ner, H., Polish J. Chem., 1998, vol. 72, p. 1907.
10. M’hlstddt, M., Bramer, R., and Schulze, B., J. Pr. Chem.,
1976, vol. 318, p. 507.
11. Schulze, B., Kirsten, G., Kirrbach, S., Rahm, A., and
Heimgartner, H., Helv. Chim. Acta, 1991, vol. 74, p. 1059;
Kirrbach, S., Doctoral Sci. (Chem.) Dissertation, Liepzig:
Liepzig University, 1994, 136 p.
12. Budzikiewich, H., Massenspectrometrie, Weinheim: Verlag
Chemie, 1980, p. 121; Vul’fson, N.S., Zaikin, V.G., and Mi-
kaya, A.I., Mass-spektrometriya Organicheskikh Soedine-
nii (Mass Spectrometry of Organic Compounds), Moscow:
Khimiya, 1986, vol. 199, p. 237.
–1
spectrum, cm : 1768, 1650, 1574, 1399, 1331, 1247, 1166,
13
1117. C NMR spectrum, d, ppm: 14.1, 20.4, 20.79, 20.84,
21.0, 63.3, 76.3 (OCH), 131.9, 155.2, 162.9, 170.6. Mass
spectrum, m/z (Irel, %): 345 (70.1) [M]+, 317 (7.1), 299
(41.4), 273 (20.0), 261 (10.0), 245 (16.4), 227 (47.1), 216
(30.7), 199 (9.3), 188 (82.1), 179 (15.0), 169 (40.0), 160
(32.1), 150 (10.7), 131 (25.7), 122 (33.6), 114 (17.1), 107
(60.0), 96 (15.0), 86 (18.6), 79 (100), 69 (21.4), 52 (28.6),
43 (30.0). Found, %: C 48.79; H 5.62; N 3.96; S 9.49.
C14H19NO7S. Calculated, %: C 48.69; H 5.50; N 4.05;
S 9.27.
3-(Diethoxycarbonylmethoxy)-5-methyl-4-
phenylisothiazole-1,1-dioxide (IVf). Colorless sub-
stance, yield 80%, mp 104–106°C (from Et2O–CH2Cl2).
–1
IR spectrum, cm : 1771, 1748, 1650, 1563, 1379, 1332,
1
1248, 1176, 1098, 1031. H NMR spectrum (0.3 mol l-1),
d, ppm: 1.28 t (6H, 2CH3, J 7.14 Hz) 2.34 s (3H, CH3C=),
4.32 q (4H, 2CH2O, J 7.14 Hz), 5.80 s (1H, OCH),
7.47 br.s (5H, Ph). 13C NMR spectrum, d, ppm: 10.5,
14.3, 63.6, 77.1 (OCH), 126.5, 129.1, 130.0, 130.6, 129.2,
152.8, 162.9, 170.8. Mass spectrum, m/z (Irel, %): 381
(45.4) [M]+, 353 (2.5), 336 (11.4), 308 (4.6), 280 (4.3),
263 (5.7), 252 (3.3), 236 (41.4), 224 (12.1), 202 (5.7), 171
(22.1), 156 (7.1), 144 (15.7), 130 (11.4), 115 (100), 105
(14.3), 89 (10.7), 77 (12.9), 65 (7.1), 51 (8.6), 43 (12.1).
Found, %: C 53.2; H 4.9; N 3.45; S 8.09. C17H19NO7S.
Calculated, %: C 53.54; H 4.98; N 3.67; S 8.39.
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RUSSIAN JOURNALOF ORGANIC CHEMISTRY Vol. 40 No. 5 2004