1-Chloro-1,3-dimethyl-1,3-diorganyl-3-(trimethylsilylamino)disiloxanes

Article abstract of DOI:10.1007/s11172-017-1856-y

The main products of the reaction of 1,3-dichloro-1,3-dimethyl-1,3-diorganyldisiloxanes with hexamethyldisilazane (molar ratio 1 : 1, 20 °C) are the earlier unknown linear 1-chloro-1,3-dimethyl-1,3-diorganyl-3-(trimethylsilylamino)disiloxanes of the general formula ClMeRSiOSiMeRNHSiMe₃ (1) (R = ClCH₂ (a), Me (b), Vin (c), Ph (d)) obtained in up to 53—72% yield and 1,3-dimethyl-1,3-diorganyl-1,3-bis(trimethylsilylamino)disiloxanes of the general formula (Me₃SiNH)MeRSiOSiMeR(NHSiMe₃) (2a—d) (7—12% yield). Thermolysis of compounds 1a—d leads to the formation of cyclic silazaoxanes. A plausible scheme for their formation was suggested.

Full text of DOI:10.1007/s11172-017-1856-y

Russian Chemical Bulletin, International Edition, Vol. 66, No. 6, pp. 1074—1077, June, 2017
1074
1-Chloro-1,3-dimethyl-1,3-diorganyl-3-(trimethylsilylamino)disiloxanes
S. V. Basenko and A. S. Soldatenko
A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences,
1 ul. Favorskogo, 664033 Irkutsk, Russian Federation.
E-mail: sv_basenko@irioch.irk.ru
The main products of the reaction of 1,3-dichloro-1,3-dimethyl-1,3-diorganyldisiloxanes
with hexamethyldisilazane (molar ratio 1 : 1, 20 C) are the earlier unknown linear 1-chloro-
1,3-dimethyl-1,3-diorganyl-3-(trimethylsilylamino)disiloxanes of the general formula
ClMeRSiOSiMeRNHSiMe3 (1) (R = ClCH2 (a), Me (b), Vin (c), Ph (d)) obtained in up to
53—72% yield and 1,3-dimethyl-1,3-diorganyl-1,3-bis(trimethylsilylamino)disiloxanes of the
general formula (Me3SiNH)MeRSiOSiMeR(NHSiMe3) (2a—d) (7—12% yield). Thermolysis
of compounds 1a—d leads to the formation of cyclic silazaoxanes. A plausible scheme for their
formation was suggested.
Key words: hexamethyldisilazane, 1,3-dichloro-1,3-dimethyl-1,3-diorganyldisiloxanes,
1-chloro-1,3-dimethyl-1,3-diorganyl-3-(trimethylsilylamino)disiloxanes, 1,3-bis(trimethyl-
silylamino)-1,3-dimethyl-1,3-diorganyldisiloxanes, cyclosilazaoxanes.
Organylsilazaoxanes are used as starting materials for
products in vacuo led to the formation of cyclosilazaoxanes,
the yield of which became almost quantitative at a pro-
longed (16—28 h) reflux. In the presence of nitrogen
bases (DMF, pyridine) and DMSO, this process requires
2—5 h. A catalytic effect of nitrogen bases on cyclization
reactions was reported earlier in the work.5
Based on gas chromatography-mass spectrometery
(GC-MS) monitoring and using reaction of 1,3-dichloro-
1,3-dimethyl-1,3-divinyldisiloxane as a model, we sug-
gested the following pathway for the process (Scheme 2).
It should be noted that in the initial stage, cyclosilaza-
oxanes 4c and 5c are formed in the ratio 2 : 1, however, as
the reaction proceeds further only the content of structure
4c is increased, while the yield of compound 5c does not
exceed 5%.
A prolonged contact (20—25 days) of 1,3-dichlorote-
traorganyldisiloxanes with hexamethyldisilazane (molar
ratio 1 : 2) at room temperature did not lead to consider-
able increase in the yield of compounds 2a—d.
The GC-MS data showed (for compound 1c as an
example) that the reflux of the reaction mixture under
conditions of incomplete proceeding of the reaction (mo-
the production of silicone oils and rubbers,1 surface
modifiers of glass, polymers, and biopolymers.2 Polymers
based on them are used as heat-resistant adhesives and
components of compositions for the preparation of chem-
ically resistant ceramic coatings for aviation and space
technology.3
In continuation of our studies4 in the area of synthesis
and examination of reactivity of 1,3-dichloro-1,3-dimeth-
yl-1,3-diorganyldisiloxanes, in the present work we found
that, in contrast to the statements made earlier,5 these
compound even at room temperature react with hexameth-
yldisilazane (molar ratio 1 : 1, 120—240 h) with a pre-
dominant formation of earlier unknown 1-chloro-1,3-
dimethyl-1,3-diorganyl-3-(trimethylsilylamino)disiloxanes
1a—d (up to 72%) together with 1,3-dimethyl-1,3-di-
organyl-1,3-bis(trimethylsilylamino)disiloxanes 2a—d
(7—12%) (Scheme 1).
A removal of chlorotrimethylsilane from the reaction
mixture by evacuation (40—50 Torr) did not considerably
affect the ratio of the reaction products, while its distilla-
tion off at normal pressure or the distillation of the reaction
Scheme 1
R = ClCH2 (a), Me (b), Vin (c), Ph (d)
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1074—1077, June, 2017.
1066-5285/17/6606-1074 © 2017 Springer Science+Business Media, Inc.

1-Chloro-3-(trimethylsilylamino)disiloxanes
Russ. Chem. Bull., Int. Ed., Vol. 66, No. 6, June, 2017
1075
Scheme 2
R = ClCH2 (a), Me (b), Vin (c), Ph (d)
lar ratio 1 : 1), i.e., in the presence of the starting 1,3-di-
chloro-1,3-dimethyl-1,3-divinyldisiloxane and hexa-
methyldisilazane, the formation of symmetrical linear
α,ω-dichloro(vinyl)silazaoxane (6c) is observed (Scheme 3),
as well as the elongation of the silazaoxane chain
(Scheme 4).
chromatography-mass spectrometry, while compounds
3c, 5c, 6c only by GC-MS. Physicochemical constants
of octamethylcyclotetrasila-4,8-diaza-2,6-dioxane and
1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasila-4,8-
diaza-2,6-dioxane agree with the corresponding constants
for ammonolysis products of 1,3-dichloro-1,1,3,3-tetra-
methyldisiloxane6,7 and 1,3-dichloro-1,3-dimethyl-1,3-
divinyldisiloxane8 obtained by the reaction with liquid
ammonia at –71—(–20) C.
Scheme 3
The fragmentation of 1-chloro-1,3-dimethyl-1,3-di-
organyl-3-(trimethylsilylamino)disiloxanes, 1,3-dimethyl-
1,3-diorganyl-1,3-bis(trimethylsilylamino)disiloxanes and
cyclosilazaoxanes follows the same directions which was
found for linear and cyclic silazane structures.9—11
Experimental
1H, 13C, and 29Si NMR spectra were recorded on a Bruker
DPX 400 spectrometer (400, 100, and 161.98 MHz, respectively)
in CDCl3, using SiMe4 as an internal standard. Reaction progress
was monitored by 1H NMR spectroscopy.
R = Vin (c)
Scheme 4
Mass spectra were recorded on a Shimadzu GCMS-QP5050A
spectrometer, injector temperature 200—250 C, carrier gas
helium, detector temperature 200 C, a quadrupole mass-ana-
lyzer, EI ionization (70 eV). Chromatographic separation of
compounds under study was carried out on a SPB-5 capillary
column (60 m×0.25 mm×0.25 m), carrier gas helium, the flow
rate 0.7 mL min–1; injector temperature 230 C, temperature of
the source of ions 200 C, pressure 280 kPa, programmed regime
from 60 to 250 C at the rate of 10 deg min–1
.
Chromatographic analysis of reaction products was carried
out by GLC on an LKhM-8M chromatograph with a 1000×0.5-mm
column filled with Chromaton-N-AW covered with the SE-30
phase (5%), carrier gas He. Injector temperature 260 C, katharo-
meter temperature 240 C. The column temperature was lin-
R = Vin (c)
early programmed from 30 to 250 C at the rate of 20 deg min–1
.
Compound 3c can be also formed by the reaction of
two molecules of 1c (see Scheme 2). Attempted isolation
of these compounds leads to their further conversion with
the formation of compound 4c.
1,3-Dichloro-1,3-dimethyl-1,3-diorganyldisiloxanes were
synthesized according to the method described earlier,4 hexa-
methyldisilazane, an industrial product, was purified by distilla-
tion. Their physical constants corresponded to the literature data.
Reaction of 1,3-dichloro-1,3-dimethyl-1,3-divinyldisiloxane
with hexamethyldisilazane. A mixture of 1,3-dichloro-1,3-dimeth-
Compounds 1a—d, 2a—d, and 4a—d were character-
1
ized by H, 13C, and 29Si NMR spectroscopy and gas

1076
Russ. Chem. Bull., Int. Ed., Vol. 66, No. 6, June, 2017
Basenko and Soldatenko
yl-1,3-divinyldisiloxane (22.6 g, 0.1 mol) with hexamethyldisi-
lazane (16.1 g, 0.1 mol) was stirred for 140 h at ~20 C. The reac-
tion was carried out in a three-neck flask with a reflux
condenser, argon was used as a reaction gas medium.
Chlorotrimethylsilane (8.9 g, 82%) was distilled off at reduced
pressure (b.p. 57 oC for distillation at normal pressure). The
conversion on hexamethyldisilazane was more than 95%. The
residue was analyzed by 1H, 13C, and 29Si NMR spectroscopy
and chromato-mass spectrometry.
1-Chloro-1,3-dimethyl-3-trimethylsilylamino-1,3-divinyl-
disiloxane, ClMeVinSiOSiMeVinNHSiMe3 (1c). The yield was
72%. 1H NMR, : 0.07 (9 H, NSiMe3); 0.15, 0.20 (3 H, CH3SiN);
0.55, 0.59 (3 H, CH3SiCl); 0.65 (NH); 5.87—6.03 (m, 6 H,
CH=CH2). 13C NMR, : 1.14 (NSiMe3), 2.73 (CH3SiN), 3.19
(CH3SiCl), 135.11—136.27 (CH=CH2). 29Si NMR, : –11.44
(OSiN), –7.57 (SiMeVinCl), 3.53 (NSiMe3). MS, m/z (Irel (%)):
264 [M – Me]+ (100), 252 [M – Vin]+ (6), 244 [M – Cl]+ (20),
228 [M – Me – HCl]+ (17), 210 (8), 156 [M – Me – ClSiMe3]+
(7), 144 (19), 132 (20), 97 (13), 85 (10), 73 Me3Si+ (7).
1,3-Dimethyl-1,3-bis(trimethylsilylamino)-1,3-divinyldisil-
oxane, (Me3SiNH)MeVinSiOSiMeVin(NHSiMe3) (2c). The yield
was 7%. 1H NMR, : 0.08 (18 H, NSiMe3); 0.13, 0.18 (6 H,
CH3SiN); 0.61 (NH); 5.79—6.12 (m, 6 H, CH=CH2). 13C NMR,
: 1.19 (NSiMe3), 2.79 (CH3SiN), 134.98—136.17 (CH=CH2).
29Si NMR, : –10.92 (OSiN), 2.70 (NHSiMe3). MS, m/z
(Irel (%)): 317 [M – Me]+ (100), 305 [M – Vin]+ (12), 289
[M – Vin – CH4]+ (35), 277 (19), 243 (35), 229 (35), 217 (97),
205 (84), 191 (11), 189 (21), 142 (19), 130 (39), 85 (55), 73
Me3Si+ (55).
1-Chloro-1,3,5,7-tetramethyl-7-trimethylsilylamino-1,3,5,7-
tetravinyl-4-aza-2,6-dioxasilane, ClMeVinSiOSiMeVinNHSiMe-
VinOSiMeVinNHSiMe3 (3c). MS, m/z (Irel (%)): 435 [M – Me]+
(21), 423 [M – Vin]+ (3), 407 [M – Vin – CH4]+ (6), 395 (7),
381 (8), 377 [M – SiMe3]+ (6), 303 (24), 287 (15), 229 (41),
217 (38), 158 (56), 105 (45), 85 (100).
1,3,5,7-Tetramethyl-1,3,5,7-tetravinylcyclotetrasila-4,8-di-
aza-2,6-dioxane, (MeVinSiO)2(MeVinSiNH)2 (4c). The yield
was 92%. 1H NMR, : 0.08—0.13 (12 H, Me); 5.89—6.11 (m, 6 H,
CH=CH2). 13C NMR, : 1.09 (CH3), 134.75—136.77 (CH=CH2).
29Si NMR, : –23.15 (OSiN). MS, m/z (Irel (%)): 342 M+ (3),
327 [M – Me]+ (100), 315 [M – Vin]+ (30), 299 [M – Vin –
–CH4]+ (18), 288 (19), 282 (8), 256 (7), 233 (6), 219 (6), 203
(6), 156 (2), 97 (11), 85 (5).
29Si NMR, : –7.23 (OSiN), –3.40 (SiMeCl), 3.57 (NHSiMe3).
MS, m/z (Irel (%)): 308 [M – Me]+ (19), 274 [M – ClCH2]+
(62), 258 [M – ClCH2 – CH4]+ (2), 238 [M – ClCH2 – HCl]+
(9), 230 (18), 194 (12), 180 (30), 166 (61), 152 (40), 132 (24),
87 (71), 73 [Me3Si+] (100).
1,3-Di(chloromethyl)-1,3-dimethyl-1,3-bis(trimethylsilyl-
amino)disiloxane, (Me3SiNH)Me(ClCH2)SiOSi(CH2Cl)
Me(NHSiMe3) (2a). The yield was 10%. 1H NMR, : 0.04
(s, SiMe3); 0.58 (s, 6 H, MeSi); 2.84—3.04 (q, 4 H, ClCH2Si).
13C NMR, : –1.78 (Me), 0.04 (SiMe3), 29.71 (ClCH2).
29Si NMR, : –6.56 (OSiN), 3.31 (NHSiMe3). MS, m/z (Irel(%)):
361 [M – Me]+ (13), 327 [M – ClCH2]+ (100), 311 [M – ClCH2
– CH4]+ (2), 291 [M – ClCH2 – HCl]+ (4), 283 (2), 252 (26),
238 (23), 218 (39), 189 (17), 146 (57), 73 [Me3Si+] (91).
1,3,5,7-Tetra(chloromethyl)-1,3,5,7-tetramethylcyclotetra-
sila-4,8-diaza-2,6-dioxane, [Me(ClCH2)SiO]2[Me(ClCH2)
SiNH]2 (4a). The yield was 83%. 1H NMR, : 0.88 (s, 6 H, MeSi);
2.74—3.91 (q, 4 H, ClCH2Si). 13C NMR, : –0.18 (Me), 29.10
(ClCH2). 29Si NMR, : –16.49 (OSiN). MS, m/z (Irel (%)): 415
[M – Me]+ (2), 381 [M – ClCH2]+ (100), 345 (12), 289 (19),
210 (13), 180 (23), 152 (13), 138 (22), 93 (14).
The reaction of 1,3-dichloro-1,1,3,3-tetramethyldisiloxane
with hexamethyldisilazane was carried out similarly (molar ratio
1 : 1). The reaction time was 200 h.
1-Chloro-1,1,3,3-tetramethyl-3-trimethylsilylaminodisilox-
ane, ClMe2SiOSiMe2NHSiMe3 (1b). The yield was 57%.
1H NMR, : 0.06 (s, 9 SiMe3); 0.21 (s, 6 H, OSiMe2N); 0.47
(s, 6 H, 2 ClSiMe2O). 13C NMR, : 1.53 (SiMe3), 2.43
(OSiMe2NH), 3.85 (ClSiMe2O). 29Si NMR, : –11.16 (OSiN),
1.99 (NSiMe3), 7.23 (ClSiMe2). MS, m/z (Irel (%)): 240
[M – Me]+ (100), 224 [M – Me – CH4]+ (7), 220 [M – Cl]+
(7), 204 [M – Me – HCl]+ (4), 188 [M – Me – HCl – CH4]+
(12), 167 [M – Me – NHSiMe2]+ (4), 132 [M – Me – ClSiMe3]+
(87), 93 (3), 73 [Me3Si+] (28).
1,1,3,3-Tetramethyl-1,3-bis(trimethylsilylamino)disiloxane,
(Me3SiNH)Me2SiOSiMe2(NHSiMe3) (2b). The yield was 10%.
1H NMR, : 0.17 (s, 18 H, SiMe3); 0.44 (s, 12 H, 2 SiMe2).
13C NMR, : 1.43 (SiMe3), 3.81 (SiMe2). 29Si NMR, : –8.78
(OSiN), 2.79 (NHSiMe3). MS, m/z (Irel (%)): 308 M+ (3), 293
[M – Me]+ (100), 277 [M – Me – CH4]+ (7), 261 (5), 227 (3),
221 (2), 205 (51), 189 (6), 146 (10), 132 (5), 130 (17), 73 [Me3Si+](20).
Octamethylcyclotetrasila-4,8-diaza-2,6-dioxane, (Me2SiO)2-
(Me2SiNH)2 (4b). The yield was 62%. 1H NMR, : 0.09 (s, 24 H,
4 SiMe2). 13C NMR, : 3.77 (SiMe2). 29Si NMR, : –12.56
(OSiN). MS, m/z (Irel (%)): 279 [M – Me]+ (100), 263 [M – Me –
– CH4]+ (25), 247 [M – Me – 2 CH4]+ (10), 233 (3), 229 (3),
227 (4), 189 (4), 175 (3), 146 (10), 132 (15), 93 (2), 73 [Me3Si+](21).
The reaction of 1,3-dichloro-1,3-dimethyl-1,3-diphenyldi-
siloxane with hexamethyldisilazane was carried out similarly
(molar ratio 1 : 1). The reaction time was 240 h.
1,3,5,7-Tetramethyl-1,3,5,7-tetravinyl-4-trimethylsilylcyclo-
tetrasila-4,8-diaza-2,6-dioxane, (MeVinSiO)2(MeVinSiNH)
(MeVinSiNSiMe3) (5c). MS, m/z (Irel (%)): 414 M+ (5), 399
[M – Me]+ (100), 387 [M – Vin]+ (59), 375 (21), 359 (10), 303 (25),
275 (9), 245 (20), 217 (12), 158 (64), 130 (38), 85 (52), 73 (68).
1,7-Dichloro-1,3,5,7-tetramethyl-1,3,5,7-tetravinyl-4-aza-
2,6-dioxasilane, ClMeVinSiOSiMeVinNHSiMeVinOSiMeVinCl
(6c). MS, m/z (Irel (%)): 397 M+ (2), 382 [M – Me]+ (17), 370
[M – Vin]+ (4), 328 (20), 302 (9), 262 (36), 250 (100), 238 (51),
214 (14), 97 (52).
1-Chloro-1,3-dimethyl-1,3-diphenyl-3-trimethylsilylamino-
disiloxane, ClMePhSiOSiMePhNHSiMe3 (1d). The yield was
1
53%. H NMR, : 0.07 (9 H, NSiMe3); 0.68, 0.73 (6 H, CH3);
The reaction of 1,3-dichloro-1,3-di(chloromethyl)-1,3-
dimethyldisiloxane with hexamethyldisilazane was carried out
similarly (molar ratio 1 : 1). The reaction time was 120 h.
1-Chloro-1,3-di(chloromethyl)-1,3-dimethyl-3-trimethyl-
silylaminodisiloxane, ClMe(ClCH2)SiOSiMe(CH2Cl)NHSiMe3
(1a). The yield was 69%. 1H NMR, : 0.05 (s, SiMe3); 0.56
(s, 3 H, MeSiN); 0.63 (s, 3 H, MeSiCl); 2.69—2.81 (q, 2 H,
ClCH2SiN); 2.89—2.99 (q, 2 H, ClCH2SiCl). 13C NMR, :
–1.88, –1.53 (CH3); 0.04 (SiMe3); 29.37, 30.00 (ClCH2).
7.25—7.53 (m, 10 H, C6H5). 13C NMR, : 1.17 (SiMe3), 2.72
(CH3), 127.78, 130.45, 132.65, 134.21 (C6H5). 29Si NMR, :
–10.14 (OSiN), –6.53 (ClSiMe), 3.09 (NSiMe3). MS, m/z
(Irel (%)): 364 [M – Me]+ (100), 344 [M – Cl]+ (18), 328
[M – Me – HCl]+ (4), 312 [M – Me – HCl – CH4]+ (7), 286
[M – Ph – CH4]+ (9), 270 [M – Ph – 2 CH4]+ (5), 256 [M – Me –
– ClSiMe3]+ (6), 197 (25) , 194 (17), 135 (24), 73 [Me3Si+] (3).
1,3-Dimethyl-1,3-diphenyl-1,3-bis(trimethylsilylamino)disil-
oxane, (Me3SiNH)MePhSiOSiMePh(NHSiMe3) (2d). The yield

1-Chloro-3-(trimethylsilylamino)disiloxanes
Russ. Chem. Bull., Int. Ed., Vol. 66, No. 6, June, 2017
1077
1
was 12%. H NMR, : 0.06 (18 H, NSiMe3); 0.83 (6 H, CH3);
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7.45—7.54 (m, 10 H, C6H5). 13C NMR, : 1.29 (SiMe3), 2.72
(CH3), 127.78, 130.45, 132.65, 134.21 (C6H5). 29Si NMR, :
–9.69 (OSiN), 3.71 (NHSiMe3). MS, m/z (Irel (%)): 432 M+.
(11), 417 [M – Me]+ (100), 401 [M – Me – CH4]+ (1), 339
[M – Ph – CH4]+ (29), 328 (14), 323 [M – Ph – 2 CH4]+ (13),
267 (49), 250 (15), 205 (25), 197 (15), 192 (26), 135 (41),
73 [Me3Si+] (10).
1,3,5,7-Tetramethyl-1,3,5,7-tetraphenylcyclotetrasila-4,8-
diaza-2,6-dioxane, [Me(Ph)SiO]2[Me(Ph)SiNH]2 (4d). The
yield was 88%. 1H NMR, : 0.82 (6 H, CH3); 7.44—7.54 (m, 10 H,
C6H5). 13C NMR, : 2.66 (CH3), 127.98, 130.84, 132.93, 134.30
(C6H5). 29Si NMR, : –10.97 (OSiN). MS, m/z (Irel (%)): 542
M+.(8), 527 [M – Me]+ (100), 511 [M – Me – CH4]+ (3), 465
[M – Ph]+ (12), 449 [M – Ph – CH4]+ (39), 432 (28), 416 (13),
371 (18), 281 (22), 217 (54), 207 (41), 178 (30), 96 (17), 69 (26).
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The main results were obtained using material and
technical facilities of Baikal Analytical Multi-access Center
of the Siberian Branch of the Russian Academy of Sciences.
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References
Received January 30, 2017;
in revised form March 1, 2017
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