New reaction of di- and trichloromethylbenzenes with orthoformic esters [6]

Full text of DOI:10.1007/s11176-005-0036-1

Russian Journal of General Chemistry, Vol. 74, No. 9, 2004, pp. 1465 1466. Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 9, 2004,
pp. 1577 1578.
Original Russian Text Copyright
2004 by M. Gazizov, K. Gazizov, Karimova, Pudovik, Nikitin, Sinyashin.
LETTERS
TO THE EDITOR
New Reaction of Di- and Trichloromethylbenzenes
with Orthoformic Esters
M. B. Gazizov, K. M. Gazizov, R. F. Karimova,
A. M. Pudovik, V. G. Nikitin, and O. G. Sinyashin
Kazan State Technological University, Kazan, Tatarstan, Russia
Arbuzov Institute of Organic and Physical Chemistry, Kazan Research Center, Kazan, Tatarstan, Russia
Received December 22, 2003
We have discovered a new reaction of di- and tri-
chloromethylbenzenes I with orthoformic esters II and
found that the product structure depends on the nature
of X, temperature, and reagent ratio. Thus, at X = H
and reagent ratio 1:2.2, the major reaction product
after 39-h heating at 225 C is acetal V. Increasing the
heating temperature to 237 C and changing the rea-
gent ratio to 1:1 favors formation of aldehyde VI. At
X = Cl, reagent ratios 1:1 and 1:3, temperature
than benzylidene chloride Ia. We suggest that the
reaction involves initial substitution of one chlorine
atom in compounds I by an alkoxy group. The result-
ing -chloroether IIIa further exchanges with ortho
ester II to form acetal V. Similar conversion of
-
chloroethers was previously described [3]. Under
more rigid temperature conditions (237 C), acetal V
acts as a dechloroalkoxylating agent toward benzyl-
idene chloride Ia. When insufficient or no ortho ester
II is present, compound IIIa undergoes thermal de-
composition into benzaldehyde (VI) and alkyl chlo-
ride VII. , -Dichloroether IIIb is much more labile
than -chloroether IIIa and decomposes into alkyl
halide VII and benzoyl chloride (VIII). The latter is
alkoxylated with the ortho ester to give ethyl benzoate
IX. Chloroacetal IV, too, is unstable and decomposes
into alkyl formate X and compound VII [4].
1
80 C, and reaction time 10 17 h, the major products
are benzoic acid chloride VIII or ester IX. Irrespec-
tive of the nature of X, alkyl formate X and alkyl
halide VII are also formed.
PhCXCl + HC(OR)
PhCX(OR)Cl + HC(OR) Cl,
2
2
3
I
II
III
IV
IIIa + II
PhCH(OR) + IV,
2
V
Reaction between compounds Ib and IIb. a.
Ratio 1:1. Trichloride Ib, 2.59 g, and 1.96 g of ortho
ester IIb was heated at 180 C for 10 h in a sealed
ampule. Distillation gave 1.73 g of a mixture of com-
V + I
2IIIa,
IIIa
IIIb
PhCHO + RCl,
1
VI
VII
pounds VIII and IX in a 2:1 ratio ( H NMR data),
bp 104 106 C (8 mm).
PhCOCl + VII,
VIII
b. Ratio 1:3. A mixture of 1.95 g of trichloride Ib
and 4.44 g of ortho ester IIb was heated at 180 C for
VIII + II
PhCOOR + IV,
1
1
7 h. Distillation gave 1.36 g of ethyl benzoate, bp
IX
20
01 102 C (10 mm Hg), n 1.5071 (published data
D
2
0
1
IV
HCOOR + VII,
[5]: bp 212.6 C, n 1.5068). H NMR spectrum
(CDCl ), , ppm: 1.25 t (3H, Me, J 7.5 Hz), 4.25 t
D
3
X
3
HH
3
(2H, OCH , J
7.5 Hz), 7.8 m (5H, Ph).
2
HH
I, III, X = H (a), Cl (b); I, III V, VII, X, R = Me (a), Et
b); IX, R = Et.
(
Benzaldehyde dimethyl acetal (Va). a. A mixture
of 2.41 g of benzylidene chloride and 3.5 g of ortho
ester IIa was heated for 39 h at 225 C in a sealed
ampule. Distillation gave 1.75 g (76%) of acetal Va,
Compounds I exhibit a clearly pronounced elec-
trophilic reactivity toward oxygen-containing organic
compounds [1, 2]. As follows of the above data,
benzotrichloride Ib is a stronger electron acceptor
2
0
bp 83 85 C (12 mm) and 208 209 C, n 1.5010
D
1
(published data [6]: bp 208 C). H NMR spectrum
1
070-3632/04/7409-1465 2004 MAIK Nauka/Interperiodica

1466
GAZIZOV et al.
1
(
CDCl ), , ppm: 3.5 s (6H, OMe), 5.3 s (1H, CH),
The H NMR spectra were measured on a Tesla
3
7
.3 m (5H, Ph).
BC-567A spectrometer (100 MHz) against TMS.
b. A mixture of 5.73 g of ortho ester IIa and
.67 g of compound IIIa was left to stand for 24 h at
0 C. Distillation gave 5.39 g (72%) of acetal Va, bp
ACKNOWLEDGMENTS
7
2
The work was financially supported by the Russian
Foundation for Basic Research (project no. 03-03-
2
0
8
2 84 C (12 mm Hg), n 1.5005.
D
3
2547).
Benzaldehyde diethyl acetal (Va). a. A mixture
of 2.42 g of compound I and 4.89 g of ortho ester IIb
was heated for 40 h at 225 C. Distillation gave 2.17 g
REFERENCES
(
1
1
(
80%) of acetal Vb, bp 87 88 C (10 mm Hg), n2
0
D
1. Comprehensive Organic Chemistry, Barton, D.H. and
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khimiya, Moscow: Khimiya, 1982, vol. 1.
2
0
.4842 (published data [6]: bp 217 221 C, n
D
1
.4843). H NMR specrrum (CDCl ), , ppm: 1.12 t
3
3
3
6H, Me, J
7.5 Hz), 3.48 q (4H, OCH , J
HH 2 HH
7
.5 Hz), 7.3 m (5H, Ph).
2. Weygand Hilgetag Organisch-chemische Experimen-
tierkunst, Hilgetag, G. and Martini, A., Eds., Leipzig:
Barth, 1964, 3rd ed.
b. A mixture of 1.79 g of ortho ester IIb and
.06 g of compound IIIb was allowed to stand for
4 h at 20 C to obtain 1.52 g (70%) of acetal Vb, bp
2
2
8
3
. Gazizov, M.B., Pudovik, M.A., Gazizov, K.M., Kari-
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p. 1577.
2
D
0
7 88 C (10 mm Hg), n 1.4839.
Benzaldehyde (VI). a. A mixture of 3.34 g of
4
. Mezheretskii, V.V., Olekhnovich, E.P., Luk’ya-
nov, S.M., and Dorofeenko, G.N., Ortoefiry v organi-
cheskom sinteze (Ortho Esters in Organic Synthesis),
Rostov-on-Don: Rostov. Gos. Univ., 1976.
compound Ia and 2.2 g of ortho ester IIa was heated
for 24 h at 237 C. Distillation gave 1.63 g (74%) of
benzaldehyde (VI), bp 70 71 C (14 mm Hg), n20
D
2
0
1
1
7
.5430 {published data [5]: 62 C (10 mm Hg), n
D
1
5. Spravochnik khimika (Chemist’s Handbook), Nikol’-
.5430}. H NMR spectrum (CDCl ), , ppm: 7.3
3
skii, B.P., Ed., Moscow: Khimiya, 1964, vol. 2.
.9 m (5H, Ph), 9.95 s (1H, CHO).
6
. Dictionary of Organic Compounds, Heilbron, J. and
Bunbury, H.M., Eds., London: Eyre and Spottswoode,
1946, vol. 1. Translated under the title Slovar’ organi-
cheskih soedinenii, Moscow: Inostrannaya Literatura,
1949, vol. 1.
b. A mixture of 1.64 g of compound Ia and 1.7 g
of acetal Va was heated for 14 h at 237 C to obtain
.92 g (85%) of compound VI, bp 70 71 C
14 mm Hg).
0
(
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 74 No. 9 2004