Reaction of N-(2,2-diarylethyl)-N-methylamine hydrobromides with trifluoroacetic acid

Full text of DOI:10.1134/S1070363207120225

ISSN 1070-3632, Russian Journal of General Chemistry, 2007, Vol. 77, No. 12, pp. 2208 2209.
Pleiades Publishing, Ltd., 2007.
Original Russian Text N.I. Kharitonova, A.S. Gazizov, A.R. Burilov, M.A. Pudovik, A.I. Konovalov, 2007, published in Zhurnal Obshchei Khimii, 2007,
Vol. 77, No. 12, pp. 2063 2064.
LETTERS
TO THE EDITOR
Reaction of N-(2,2-Diarylethyl)-N-methylamine Hydrobromides
with Trifluoroacetic Acid
N. I. Kharitonova, A. S. Gazizov, A. R. Burilov, M. A. Pudovik, and A. I. Konovalov
Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Center, Russian Academy of Sciences,
ul. Akademika Arbuzova 8, Kazan, Tatarstan, 420088 Russia
Received April 10, 2007
DOI: 10.1134/S1070363207120225
Recently we have developed a procedure for
preparing N-(2,2-diarylethyl)-N-methylamines Ia and
Ib by the reaction of resorcinol or its derivatives with
N-[2,2-Bis(2,4-dihydroxyphenyl)]ethyl-N-methyl-
trifluoroacetamide IIa. A mixture of 0.40 g of com-
pound Ia and 10 ml of trifluoroacetic acid was re-
fluxed for 3 days. Excess acid was removed in a
vacuum, and the residue was treated with diethyl
ether. The light yellow crystals thus obtained were
separated and dried in a vacuum to give 0.35 g (85%)
-amino acetals [1]. To assess the possibility of selec-
tive N- or O-functionalization of such compounds,
we studied the reactions of amine hydrobromides Ia
and Ib with acetic and trifluoroacetic acids. Com-
pounds Ia and Ib do not react with acetic acid,
whereas prolonged heating of these substances with
trifluoroacetic acid yields N-acylation products IIa
1
of compound IIa, mp 125 C. IR spectrum, , cm :
1
13
1
and IIb. Their structure was confirmed by H,
C
1615 (CHarom), 1679 (C=O), 3347 (OH). H NMR
NMR and IR spectroscopy, and their composition
was determined by elemental analysis.
spectrum (CD OD), , ppm (J, Hz): 2.61 s, 2.64 s,
3
2
.66 s (3H, NCH ), 3.58 m (2H, CH N), 4.82 m (1H,
3 2
1
,5
R
CH), 6.26 6.44 m (4H, C Harom), 6.87 6.94 m (2H,
CH Harom). 13C NMR spectrum (acetone-d6), C, ppm:
R
4
HO
OH HO
OH
+
CF COOH
3
9
7
8
1
3
1
4.23 (C ), 36.43 (C ), 53.08 (C ), 104.02 (C
),
arom
CH
07.92 (C5 ), 116.40 (C ), 118.29 (C
), 155.76, 156.67 (C
61.29 (C ). Found, %: C 54.69; H 4.35; N 3.80.
11
3
), 130.70
arom
arom
CH2
4
6
2
(C
), 158.30 (C
),
arom
arom
arom
CH NH HBr
3
10
1
Ia, Ib
C H NO F . Calculated, %: C 54.98; H 4.31;
1
7
16
5 3
R
N 3.77.
R
1
HO 6
2
OH HO
OH
N-[2,2-Bis(2,4-dihydroxy-3-methylphenyl)]ethyl-
N-methyltrifluoroacetamide IIb was prepared
similarly by heating of 0.77 g of compound Ib and
3
7
CH
5
4
8
CH2
9
10 11
10 ml of trifluoroacetic acid. Yield 0.40 g (50%),
CH N C CF
3
3
yellow crystals, mp 105 C. IR spectrum, , cm 1:
O
1
1
614 (CHarom), 1674 (C=O), 3342 (OH). H NMR
IIa, IIb
spectrum (D O), , ppm (J, Hz): 1.95 s, 1.99 s, 2.04 s,
2
2
.05 s, 2.09 s, 2.11 s (6H, CaromCH ), 2.56 s, 2.60 s,
3
I, II, R = H (a); Me (b).
2.68 s (3H, NCH ), 3.58 m (2H, CH N), 4.86 m (1H,
3 2
2208

REACTION OF N-(2,2-DIARYLETHYL)-N-METHYLAMINE HYDROBROMIDES
2209
CH), 6.25 6.88 m (4H, C H ). 13C NMR spec-
4,5
ACKNOWLEDGMENTS
arom
9
trum (CD OD), , ppm: 9.07, 9.88 (CH ), 34.05 (C ),
3
C
3
7
8
1
5
The study was financially supported by the Russian
Foundation for Basic Research, project no. 05-03-
32136.
3
1
1
7.09 (C ), 53.70 (C ), 108.37 (C
), 114.66 (C
),
arom
arom
19.78 (C3 ), 121.21 (C ), 126.22 (C
11
4
), 154.43,
arom
arom
53.52 (C a6 rom), 156.38 (C
2
10
), 162.28 (C ). Found,
arom
%
: C 57.34; H 4.97; N 3.51. C H NO F . Cal-
19 20 5 3
REFERENCES
culated, %: C 57.14; H 5.01; N 3.50.
1
The H NMR spectra were taken in D O and
1. Burilov, A.R., Gazizov, A.S., Volodina, Yu.M., Pudo-
vik, M.A., Habicher, W.D., Baer, I., Gubaidullin, A.T.,
Litvinov, I.A., and Konovalov, A.I., Mendeleev
Commun., 2005, no. 4, p. 153.
2
1
3
CD OD, and C NMR spectra, in (CD ) C=O and
CD OD on a Bruker Avance-600 spectrometer (600
and 150 MHz, respectively).
3
3 2
3
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 77 No. 12 2007