2
A.Y. Nikonov et al. / Journal of Molecular Structure 1198 (2019) 126782
Scheme 1. Compound 2 was synthesized by the reaction of 2-(trimethylsilyloxy)aniline 5 and 4-chlorobenzenesulfonyl chloride in benzene at 40e50 ꢀC (Scheme 2).
Scheme 2. The structure of compounds 1 and 2 was investigated by NMR and IR spectroscopy, and X-ray diffraction analysis.
with hexane (10 ml) and dried in vacuo. Resulted product was
melted and after cooling the crystals of (1) were obtained in 90%
yield.
were dried and freshly distilled under argon prior to use [40].
2.1. Synthesis and crystallization
b) The
mixture
of
N-(2-hydroxyphenyl)-4-
methylbenzenesulfonamide 3 (2.5 g, 9.5 mmol) and the excess
of hexamethyldisilazane (2.0 g, 12.4 mmol) was refluxed for
24 h. Resulted product was dried in vacuo to give 3.4 g of viscous
residue. NMR analysis revealed the product as a mixture of N-
[(2-(trimethylsilyl)oxy)phenyl]-4-methylbenzenesulfonamide
(1) and N-(trimethylsilyl)-N-[(2-(trimethylsilyl)oxy)phenyl]-4-
methylbenzenesulfonamide (4) with ratio 1:1 with total con-
version of 3 about 97%. Reaction of 2.1 g of 3 (8 mmol) with
0.65 g (4 mmol) of hexamethyldisilazane resulted in obtaining of
almost pure compound 1 in ~97% yield (2.62 g).
2.1.1. N-(2-hydroxyphenyl)-4-methylbenzenesulfonamide 3
Compound 3 was synthesized as described in Refs. [41,42]. To
the vigorously stirred emulsion of o-aminophenol (3 g, 27.5 mmol)
and pyridine (2.2 g, 27.8 mmol) in CH2Cl2 (50 ml) the solution of
tosyl chloride (5.3 g, 27.8 mmol) in CH2Cl2 (30 ml) was added
dropwise. After stirring for 2 h at room temperature, the mixture
was washed with water (100 ml), the organic layer was separated,
dried over magnesium sulfate, filtered and concentrated in vacuum
to give crude solid residue. After crystallization from CH2Cl2, pure
N-(2-hydroxyphenyl)-4-methylbenzenesulfonamide
3 was ob-
tained in ~93% yeld (6.7 g). 1H NMR (CDCl3,
d, ppm): 2.38 (s, 3H,
N-[(2-(Trimethylsilyl)oxy)phenyl]-4-
CH3C6H4SO2), 6.42 (br. s, 1H, OH), 6.56 (s, 1H, NH), 6.72 (m, 1H,
C6H4OH), 6.81 (m, 1H, C6H4OH), 6.90 (m, 1H, C6H4OH), 7.06 (m, 1H,
C6H4OH), 7.23 (m, 2H, 4-CH3С6H4), 7.54 (m, 1H, 4-CH3С6H4), 7.60
methylbenzenesulfonamide (1). 1H NMR (CDCl3,
d, ppm): 0.16 (s,
9H, (CH3)3SieO), 2.35 (s, 3H, CH3C6H4SO2), 6.66 (m, 1H, ArO),
6.86e6.96 (m, 2H, ArO), 7.18 (m, 2H, 4-CH3С6H4), 7.54 (m, 1H, ArO),
(m, 2H, 4-CH3С6H4). Anal. calcd. for C13H13NO3S: C, 59.30; H, 4.98;
N, 5.32. Found: C, 58.92; H, 4.67; N, 5.41.
7.61 (m, 2H, 4- CH3С6H4). 13C NMR (CDCl3,
d, ppm): 0.75
((CH3)3SieO), 21.35 (CH3C6H4SO2), 117.42 (C3), 121.75 (C6), 121.95
(C5), 125.33 (C4), 127.34 (Cm 4-CH3С6H4), 127.93 (C1), 129.63 (Co 4-
CH3С6H4), 136.68 (Cp 4-CH3С6H4), 143.85 (Ci 4-CH3С6H4), 145.88
2.1.2. N-[(2-(Trimethylsilyl)oxy)phenyl]-4-
methylbenzenesulfonamide (1) and N-(trimethylsilyl)-N-[(2-
(trimethylsilyl)oxy)phenyl]-4-methylbenzenesulfonamide (4)
(C2). 29Si NMR (CDCl3,
d
, ppm): 21.8 ((CH3)3SieO). Anal. calcd. for
16H21NO3SSi: C, 57.28; H, 6.31; N,4.17. Found: C, 57.61; H, 6.54; N,
4.11.
C
a) Chlorotrimethylsilane (0.9 g, 8.2 mmol) in 10 ml of benzene was
N-(Trimethylsilyl)-N-[(2-(trimethylsilyl)oxy)phenyl]-4-
added dropwise under stirring to
hydroxyphenyl)-4-methylbenzenesulfonamide
a
solution of N-(2-
(2.1 g,
methylbenzenesulfonamide (4).
1H NMR (CDCl3,
d, ppm): 0.11 (s, 9H, (CH3)3SieO), 0.27 (s, 9H,
3
8 mmol) in 30 ml of benzene with 1 g of triethylamine. The re-
action mixture was stirred for 6 h with moderate heating
(40e50 ꢀC). After cooling to room temperature a precipitate of
Et3N$HCl was filtered off and washed with 50 ml of benzene.
The solvent was evaporated in vacuo. A residue was washed
(CH3)3SieN) 2.36 (s, 3H, CH3C6H4SO2), 6.62 (m, 1H, ArO), 6.82e6.88
(m, 2H, ArO), 7.13 (m, 2H, 4-CH3С6H4), 7.54 (m, 1H, ArO), 7.61 (m,
2H, 4-CH3С6H4). 13C NMR (CDCl3,
d, ppm): 0.13 ((CH3)3SieO), 1.03
((CH3)3SieN) 21.40 (CH3C6H4SO2), 117.72 (C3), 121.75 (C6), 121.95