A new synthetic method for diphenacyl telluride Synthesis of some new organotellurium compounds containing Ar-COCH(R) groups via α-tellurocynatoketones

Article abstract of DOI:10.1016/S0022-328X(03)00152-9

A new series of organotellurocyanate containing Ar-COCH(R) groups (i.e., C₆H₅COCH₂TeCN (1), 4-BrC₆H₄COCH₂TeCN 2), 4-PhC₆H₄COCH₂TeCN (3) and C₆H₅COCH(CH₃)TeCN (4)) were prepared by reacting KTeCN with the appropriate α-bromoketone in dry DMSO solution. Treatment of 1, 2, 3 and 4 with 10% NaOH afforded ditellurides 5, 6, 7 and 8 in high yields. Refluxing the ditelluride with activated copper powder in dry dioxane gave the corresponding tellurides (9, 10, 11 and 12) in good yields. Treatment of tellurides with thionyl chloride, bromine and iodine gave the dichloride (13-16), dibromide (17-20) and diiodide (21-24), respectively, in high yields. Both, tellurocyanate (1-4) and ditelluride (5-8) gave the trichloride (25-28), tribromide (29-32) and triiodide (33-36) when reacted with SOCl₂, Br₂ and I₂, respectively. Treatment of 9-16 with m-chloroperbenzoic acid (MCPBA) afforded the corresponding alkyl aryl ketones in fair to good yields. All the compounds were characterized by elemental analysis and spectroscopic data.

Full text of DOI:10.1016/S0022-328X(03)00152-9

Journal of Organometallic Chemistry 673 (2003) 40Á46
/
www.elsevier.com/locate/jorganchem
A new synthetic method for diphenacyl telluride
Synthesis of some new organotellurium compounds containing
ArÃCOCH(R) groups via a-tellurocynatoketones
/
Ali Z. Al-Rubaie a,*, Lina Z. Yousif b, Ammar K. Al-Ba’aj b
a Department of Chemistry, College of Arts and Science, Ererian, Garian, P.O. Box 64200, Libya
b Department of Chemistry, College of Science, University of Basrah, Basrah, Iraq
Received 27 July 2002; received in revised form 19 February 2003; accepted 9 March 2003
Abstract
A new series of organotellurocyanate containing ArÃ
/COCH(R) groups (i.e., C6H5COCH2TeCN (1), 4-BrC6H4COCH2TeCN (2),
4-PhC6H4COCH2TeCN (3) and C6H5COCH(CH3)TeCN (4)) were prepared by reacting KTeCN with the appropriate a-
bromoketone in dry DMSO solution. Treatment of 1, 2, 3 and 4 with 10% NaOH afforded ditellurides 5, 6, 7 and 8 in high
yields. Refluxing the ditelluride with activated copper powder in dry dioxane gave the corresponding tellurides (9, 10, 11 and 12) in
good yields. Treatment of tellurides with thionyl chloride, bromine and iodine gave the dichloride (13Á
diiodide (21Á24), respectively, in high yields. Both, tellurocyanate (1Á4) and ditelluride (5Á8) gave the trichloride (25Á
tribromide (29Á32) and triiodide (33Á36) when reacted with SOCl2, Br2 and I2, respectively. Treatment of 9Á16 with m-
/
16), dibromide (17Á/20) and
/
/
/
/28),
/
/
/
chloroperbenzoic acid (MCPBA) afforded the corresponding alkyl aryl ketones in fair to good yields. All the compounds were
characterized by elemental analysis and spectroscopic data.
# 2003 Elsevier Science B.V. All rights reserved.
Keywords: Potassium tellurocyanate; Telluride; Ditelluride; Phenacyl group
1. Introduction
A few publications [1Á
We are currently interested in potassium tellurocya-
nate as tellurating agent for preparing some organotel-
/3] have reported unsuccessful
lurium compounds [7Á9]. We now report a novel
/
preparative method for diphenacyl telluride and related
substances using a-tellurocyanatoalkyl aryl ketones as
starting materials.
attempts for the preparation of diphenacyl telluride via
reduction of diphenacyltellurium dichloride, which in
turn was prepared from the reaction of TeCl4 with
acetophenone, with a variety of mild reducing agents.
Photodecomposition of diphenacyltellurium dichloride
did not afford the corresponding telluride [4], although
diphenacyl telluride is regarded as an unstable inter-
mediate in a non-silver implication process upon physi-
cal development of photography [5]. Engman [6]
reported for the first time a successful method for the
synthesis of diphenacyl telluride by a mild Na2S2O5
reduction of diphenacyltellurium dichloride in a two-
phase system.
2. Experimental
2.1. Physical measurements
1H- and 13C-NMR spectra were obtained with a
JEOL EX-90FT NMR spectrometer instrument and
were recorded in CDCl3 solutions containing TMS as
internal standard. Infrared (IR) spectra were recorded
for KBr discs with a Pye-Unicam SP3-300s instrument.
Elemental analyses (C, H and N) were obtained for all
compounds on a Carlo-Ebra EA-1108B Elemental
Analyzer. Conductivities were measured with WTW
* Corresponding author. Tel.: ꢀ
60054.
E-mail address: alrubaie49@yahoo.com (A.Z. Al-Rubaie).
/
218-451-63231; fax: ꢀ218-451-
/
0022-328X/03/$ - see front matter # 2003 Elsevier Science B.V. All rights reserved.
doi:10.1016/S0022-328X(03)00152-9

A.Z. Al-Rubaie et al. / Journal of Organometallic Chemistry 673 (2003) 40Á
/46
41
conductivity meter LBR, using a cell constant of 0.80
cmꢁ1. Melting points for all solid compounds were
determined by Gallenkamp melting point apparatus and
are uncorrected. Molecular weight was measured in
benzene using Kanure Cryscopic meter and benzene was
used as a standard reference. Mass spectra were
determined on a Finnigan MAT-321 spectrometer at
70 eV and measurements were carried out on 130Te
isotope. Tellurium analyses were carried out by the use
of a Shimadzu-AA 630-3z atomic absorption spectro-
photometer as described previously [10].
Found: C, 30.62; H, 1.70; N, 3.76; Te, 36.42%.
2.2.3. 4-Phenylphenacyl tellurocyanate, 4-
PhC6H4COCH2TeCN (3)
Yellow solid, 59% yield, m.p. 121Á123 8C.
/
IR (cmꢁ1, KBr): nCO 1655s; nCN 2170s.
1H-NMR (d, CDCl3): 4.50 (s, CH2, 2H; J
/
ꢃ
/
125Teꢁ1H
26.8 Hz); 7.12Á
/
8.40 (m, Ar Ã
/
H, 9H).
13C-NMR (d, CDCl3): 40.2, 118.4, 127.5, 128.0, 134,
6, 136.0, 141.5, 145.2, 198.1.
Anal. Calc. for C15H11NOTe: C, 51.64; H, 3.17; N,
4.01; Te, 36.58%.
Found: C, 52.12; H, 3.96; N, 3.36; Te, 36.44%.
2.2. Synthesis
Phenacyl bromide, 4-bromophenacyl bromide, 4-phe-
nylphenacyl bromide and a-bromopropiophenone were
commercial products.
2.2.4. Propiophenon-2-yl tellurocyanate,
C6H5COCH(CH3)TeCN (4)
Yellow solid, 39% yield, m.p. 89Á90 8C.
/
IR (cmꢁ1, KBr): nCO 1630s; nCN 2160s.
2.2.1. Phenacyl tellurocyanate, C6H5COCH2TeCN (1)
A mixture of freshly crushed and finely ground
tellurium powder (1.02 g; 8 mmol) and dry powdered
potassium cyanide (0.53 g; 8 mmol) in dry DMSO (15
cm3) was refluxed under nitrogen atmosphere with
stirring for 1 h. The resulting solution was cooled to
room temperature (r.t.) and to it added a solution of
phenacyl bromide (1.59 g; 8 mmol) in 15 cm3 of dry
DMSO dropwise over a period of 30 min. After stirring
for 2 h at r.t., the yellow solution was filtered, poured
into water (300 cm3) and left for 12 h. Extraction with
1H-NMR (d, CDCl3): 2.10 (d, CH3, 3H; JHH
ꢃ14.1
/
Hz); 5.50 (q, CH, 1H); 7.41Á
/
8.25 (m, Ar Ã
/
H, 5H).
13C-NMR (d, CDCl3): 28.3, 53.2, 116.8, 128.5, 129.0,
133.2, 137.5, 200.5.
Anal. Calc. for C10H9NOTe: C, 41.88; H, 3.16; N,
4.88; Te, 44.49%.
Found: C, 42.01; H, 3.30; N, 5.00; Te, 44.14%.
2.2.5. Diphenacyl ditelluride, (C6H5COCH2)2Te2 (5)
To a solution of 1 (0.28 g; 1.02 mmol) in dry ethanol
(25 cm3) was added a solution of sodium hydroxide
(0.16 g; 2.45 mmol) in 15 cm3 of dry ethanol. The
resulting mixture was stirred for 50 min at 40 8C under
oxygen atmosphere. The solution was then refluxed for
1 h, cooled to r.t. and filtered. The filtrate was acidified
with 10% hydrochloric acid. A red semisolid compound
was formed, washed with a small amount of benzene
and dried. Recrystallization from a mixture of methanol
and dichloromethane (1:4) gave a red semisolid com-
pound in 39% yield.
benzene (4ꢂ
100 cm3) gave a pale yellow solution,
/
which was dried (MgSO4) and filtered. The filtrate was
evaporated to give a yellow precipitate. Recrystalliza-
tion from a mixture of ethanol and chloroform (3:2)
gave compound 1 as a yellow solid in 35% yield, m.p.
71Á72 8C.
/
IR (cmꢁ1, KBr): nCO 1650s; nCN 2210s.
1H-NMR (d, CDCl3): 4.65 (s, CH2, 2H; J
/
ꢃ
/
125Teꢁ1H
29.1 Hz); 7.30Á
/
8.10 (m, Ar Ã
/
H, 5H).
13C-NMR (d, CDCl3): 49.5, 116.5, 128.4, 129.1,
132.5, 137.6, 198.3.
IR (cmꢁ1, KBr): nCO 1695m; nTeÃC 475w, 530w.
1H-NMR (d, CDCl3): 4.41 (s, CH2, 4H; J
/
ꢃ
/
125Teꢁ1H
Anal. Calc. for C9H7ONTe: C, 39.63; H, 2.58; N,
5.13; Te, 46.8. Found: C, 39.46; H, 2.98; N, 5.15; Te,
46.4%.
The following compounds were prepared similarly
using the appropriate a-bromoketone.
26.8 Hz); 7.20Á
/
8.00 (m, Ar Ã
/
H, 10H).
13C-NMR (d, CDCl3): 37.4, 128.5, 129.2, 132.2,
137.3, 198.1.
Anal. Calc. for C16H14O2Te2: C, 38.94; H, 2.85; Te,
51.71%.
Found: C, 39.20; H, 2.64; Te, 52.11%.
2.2.2. 4-Bromophenacyl tellurocyanate, 4-
BrC6H4COCH2TeCN (2)
Yellow solid, 57% yield, m.p. 106 8C.
IR (cmꢁ1, KBr): nCO 1650s; nCN 2210s.
2.2.6. Bis(4-bromophenacyl) ditelluride, (4-
BrC6H4COCH2)2Te2 (6)
1H-NMR (d, CDCl3): 4.40 (s, CH2, 2H; J
/
ꢃ
/
Red solid in 67% yield, m.p. 97Á99 8C.
/
125Teꢁ1H
34.4 Hz); 7.65 (q, Ar Ã
/
H, 4H).
13C-NMR (d, CDCl3): 42.8, 117.7, 126.5, 130.0,
132.2, 133.0, 196.5.
IR (cmꢁ1, KBr): nCO 1685s; nTeÃC 480w, 530w.
1H-NMR (d, CDCl3): 4.34 (s, CH2, 4H; J
/
ꢃ
/
125Teꢁ1H
35.8 Hz); 7.62 (q, Ar Ã
/
H, 8H).
13C-NMR (d, CDCl3): 36.5, 126.1, 130.0, 132.2,
133.2, 198.5.
Anal. Calc. for C9H6NOBrTe: C, 30.74; H, 1.72; N,
3.98; Te, 36.29%.

42
A.Z. Al-Rubaie et al. / Journal of Organometallic Chemistry 673 (2003) 40Á46
/
Anal. Calc. for C16H12O2Br2Te2: C, 29.51; H, 1.86;
Te, 39.18%.
Found: C, 29.38; H, 1.85; Te, 38.82%.
Anal. Calc. for C16H12O2Br2Te: C, 36.69; H, 2.31; Te,
24.37%.
Found: C, 36.38; H, 2.28; Te, 23.92%.
2.2.7. Bis(4-phenylphenacyl) ditelluride, (4-
PhC6H4COCH2)2Te2 (7)
2.2.11. Bis(4-phenylphenacyl) telluride, (4-
PhC6H4COCH2)2Te (11)
Red solid, 76% yield, m.p. 107 8C.
Yellow crystals, 74% yield, m.p. 138Á
IR (cmꢁ1, KBr): nCO 1730s, 1620s; nTeÃC 485w, 510w.
1H-NMR (d, CDCl3): 4.45 (s, CH2, 4H; J
/
139 8C.
IR (cmꢁ1, KBr): nCO 1650s; nTeÃC 480w, 510w.
1H-NMR (d, CDCl3): 4.47 (s, CH2, 4H; J
/
ꢃ
/
/
ꢃ
/
125Teꢁ1H
125Teꢁ1H
34.0 Hz); 7.20Á
/
8.35 (m, Ar Ã
/
H, 18H).
32.2 Hz); 7.10Á
/
8.37 (m, Ar Ã
/
H, 18H).
13C-NMR (d, CDCl3): 37.4, 127.1, 127.6, 128.0,
128.5, 136.2, 141.4, 145.5, 197.5.
13C-NMR (d, CDCl3): 30.9, 127.3, 127.4, 128.5,
129.0, 129.5, 132.6, 139.5, 146.5, 195.5.
Anal. Calc. for C28H22O2Te2: C, 52.08; H, 3.43; Te,
39.52%.
Anal. Calc. for C28H22O2Te: C, 64.91; H, 4.27; Te,
24.63%.
Found: C, 64.65; H, 4.28; Te, 24.37%.
Found: C, 52.10; H, 3.42; Te, 39.26%.
2.2.8. Bis(propiophenon-2-yl) ditelluride,
(C6H5COCH(CH3))2Te2 (8)
2.2.12. Bis(propiophenon-2-yl) telluride,
(C6H5COCH(CH3))2Te (12)
Red solid, 60% yield, m.p. 60Á
IR (cmꢁ1, KBr): nCO 1665s; nTeÃC 495w, 535w.
1H-NMR (d, CDCl3): 1.71 (d, CH3, 6H; JHH
/
62 8C.
Yellow crystals, 56% yield, m.p. 70Á
IR (cmꢁ1, KBr): nCO 1700m, 1665m; nTeÃC 470w,
530w.
1H-NMR (d, CDCl3): 2.01 (d, CH3, 6H; JHH
/
71 8C.
ꢃ
/
12.1
Hz); 5.25 (q, CH, 2H); 7.20Á
/
8.10 (m, Ar Ã
/
H, 10H).
13C-NMR (d, CDCl3): 35.0, 49.1, 128.0, 129.0, 130.2,
133.6, 135.4, 197.2.
ꢃ13.7);
/
5.30 (q, CH, 2H); 7.15Á
/
8.10 (m, Ar Ã
/
H, 10H).
13C-NMR (d, CDCl3): 37.0, 48.0, 130.5, 129.0, 130.2,
131.3, 132.4, 135.2, 199.6.
Anal. Calc. for C18H18O2Te2: C, 41.45; H, 3.47; Te,
48.93%.
Found: C, 42.10; H, 3.42; Te, 49.14%.
Anal. Calc. for C18H18O2Te: C, 54.88; H, 4.60; Te,
32.39%.
Found: C, 54.95; H, 4.49; Te, 32.17%.
2.2.9. Diphenacyl telluride, (C6H5COCH2)2Te (9)
A solution of diphenacyl ditelluride (0.98 g; 2 mmol)
and activated copper (0.38 g; 6 mmol) in dry dioxane (20
cm3) was refluxed for 3 h. The reaction mixture was
filtered hot. The filtrate was allowed to cool to r.t. and
the solution was evaporated to dryness. The resulting
yellow solid was recrystallized from petroleum ether
2.2.13. Synthesis of diorganyltellurium dichloride (13,
14, 15, 16)
Compounds 13, 14, 15 and 16 were prepared by the
following method:
To a solution of the corresponding telluride (1.5
mmol) in dry diethyl ether (10 cm3) was added slowly
with stirring a solution of thionyl chloride (1.5 mmol) in
20 cm3 of dry diethyl ether. A pale yellow precipitate
was formed during the addition. Evaporation of the
solvent gave a pale yellow solid. Recrystallization from
ethanol/chloroform (1/3) gave a white crystal of the
corresponding dichloride (Table 1).
(60Á
80 8C (Lit. [6], 78Á
IR (cmꢁ1, KBr): nCO 1730m, 1650s; nTeÃC 475w,
530w.
1H-NMR (d, CDCl3): 4.55 (s, CH2, 4H; J
/
80 8C) to give yellow crystals in 67% yield, m.p. 78Á
/
/
79 8C).
/
ꢃ
/
125Teꢁ1H
25.1 Hz); 7.20Á
/
8.05 (m, Ar Ã
/
H, 10H).
13C-NMR (d, CDCl3): 35.8, 128.7, 129.9, 132.7,
137.5, 197.8.
2.2.14. Synthesis of diorganyltellurium dibromide (17,
18, 19, 20)
Compounds 17, 18, 19 and 20 were prepared accord-
ing to the following method:
Anal. Calc. for C16H14O2Te: C, 52.52; H, 3.85; Te,
34.87%.
Found: C, 52.37; H, 3.94; Te, 35.14%.
To a solution of the corresponding telluride (2 mmol)
in 20 cm3 of dry diethyl ether was added drop by drop a
solution of bromine (1.28 g; 8 mmol) in 40 cm3 of dry
diethyl ether. A fine yellow precipitate was formed
immediately and soon became almost colourless. Bro-
mine was added until a permanent colour of bromine
resulted when an additional drop of bromine was added.
The solvent was allowed to evaporate at r.t. and a yellow
precipitate of the corresponding dibromide was ob-
tained. The product was recrystallized from ethanol
2.2.10. Bis(4-bromophenacyl) telluride, (4-
BrC6H4COCH2)2Te (10)
Yellow crystals, 77% yield, m.p. 130Á
131Á132 8C).
IR (cmꢁ1, KBr): nCO 1700s, 1640s; nTeÃC 485w, 525w.
1H-NMR (d, CDCl3): 4.35 (s, CH2, 4H; J
/
132 8C (Lit. [6],
/
/
ꢃ
/
125Teꢁ1H
34.9 Hz); 7.75 (q, Ar Ã
/
H, 8H).
13C-NMR (d, CDCl3): 36.4, 126.1, 129.8, 132.2,
133.0, 197.6.

A.Z. Al-Rubaie et al. / Journal of Organometallic Chemistry 673 (2003) 40Á
/46
43
Table 1
Physical and analytical data for compounds 13Á
/36
c
Compounds
Colour Melting point (8C) Yield (%) a Analysis (%) b
Molar conductivity (LM)
C
H
Te
(C6H5COCH2)2TeCl2 (13)
(4-BrC6H4COCH2)2TeCl2 (14)
(4-PhC6H4COCH2)2TeCl2 (15)
White 192Á
White 202Á
White 154Á
/
193
203
155
154
203
212
212
201
254
259
161
224
243
152
142
147
204
137
133
131
156
130
137
173
87(89)
83(87)
80(87)
60(76)
80(82)
82(88)
82(91)
71(84)
88(83)
89(93)
76(79)
62(87)
90(88)
92(95)
80(86)
52(73)
83(85)
83(88)
85(87)
54(65)
84(80)
87(79)
89(89)
59(55)
44.01(43.99) 3.30(3.23) 29.32(29.21) 18.1
32.57(32.32) 2.37(2.03) 21.25(21.46) 18.2
57.01(57.10) 3.80(3.76) 21.45(21.66) 21.1
46.88(46.50) 4.12(3.90) 27.21(27.45) 18.0
36.72(36.56) 2.56(2.68) 23.96(24.27) 24.9
27.88(28.11) 1.68(1.76) 18.53(18.67) 20.0
49.42(49.61) 3.23(3.27) 18.65(18.82) 24.9
39.23(39.04) 3.23(3.27) 23.32(23.04) 19.5
31.78(31.01) 2.30(2.27) 40.75(40.96) 28.5
24.63(24.71) 1.52(1.55) 16.21(16.40) 32.3
37.38(37.53) 2.52(2.49) 16.52(16.53) 38.0
32.88(33.37) 2.86(2.80) 19.43(19.70) 30.0
26.95(27.21) 2.02(1.99) 35.82(36.14) 13.2
22.42(22.24) 1.37(1.39) 29.62(29.54) 24.0
38.86(39.17) 2.63(2.58) 29.50(29.75) 22.4
29.48(29.41) 2.81(2.47) 35.11(34.76) 20.1
19.99(19.75) 1.38(1.45) 25.78(26.23) 28.0
17.27(17.26) 1.40(1.07) 22.45(22.57) 27.9
30.38(29.89) 2.23(1.97) 22.75(22.68) 24.1
21.46(21.59) 1.72(1.81) 25.32(25.50) 29.1
14.99(15.31) 1.38(1.12) 20.03(20.34) 30.0
13.20(13.60) 1.12(0.85) 18.23(18.06) 40.0
23.72(23.90) 1.29(1.57) 17.65(18.14) 51.0
16.73(16.85) 1.21(1.41) 19.72(19.89) 30.1
/
/
(C6H5COCH(CH3))2TeCl2 (16) White 152Á
/
(C6H5COCH2)2TeBr2 (17)
(4-BrC6H4COCH2)2TeBr2 (18)
(4-PhC6H4COCH2)2TeBr2 (19)
Orange 201Á
Yellow 210Á
Yellow 210Á
/
/
/
(C6H5COCH(CH3))2TeBr2 (20) Yellow 200Á
/
(C6H5COCH2)2TeI2 (21)
(4-BrC6H4COCH2)2TeI2 (22)
(4-PhC6H4COCH2)2TeI2 (23)
(C6H5COCH(CH3))2TeI2 (24)
C6H5COCH2TeCl3 (25)
Red
253Á
/
Orange 257Á
/
Red
Red
160Á
/
220Á
/
White 242Á
White 150Á
White 140Á
White 145Á
Yellow 202Á
Yellow 135Á
Yellow 131Á
Yellow 130Á
/
4-BrC6H4COCH2TeCl3 (26)
4-PhC6H4COCH2TeCl3 (27)
C6H5COCH(CH3)TeCl3 (28)
C6H5COCH2TeBr3 (29)
/
/
/
/
4-BrC6H4COCH2TeBr3 (30)
4-PhC6H4COCH2TeBr3 (31)
C6H5COCH(CH3)TeBr3 (32)
C6H5COCH2TeI3 (33)
/
/
/
Red
Red
Red
Red
155Á
129Á
135Á
171Á
/
4-BrC6H4COCH2TeI3 (34)
4-PhC6H4COCH2TeI3 (35)
C6H5COCH(CH3)TeI3 (36)
/
/
/
a
Yields by using diorganyl ditellurides as starting materials are in parentheses.
Calculated values are in parentheses.
b
c
10ꢁ3 M solutions: Et4NCl LM (DMSO): 30 Vꢁ1 cm2 molꢁ1
.
and chloroform (1:1) to give yellow crystals in good
yield. Physical and analytical data are presented in
Table 1.
2.2.17. Synthesis of organyltellurium tribromide (29, 30,
31, 32)
Compounds 29, 30, 31 and 32 were prepared by the
treatment of aryltellurocyanate (1.5 mmol) with bro-
mine (1.5 mmol) as described for the preparation of the
dibromide to give a yellow product. Recrystallization
from ethanol and chloroform (1:1) gave a yellow solid in
good yield (Table 1).
2.2.15. Synthesis of diorganyltellurium diiodide (21, 22,
23, 24)
Compounds 21, 22, 23 and 24 were prepared as
follows:
Iodine (0.39 g; 1.5 mmol) in dry diethyl ether (15 cm3)
was added to a well stirred solution of the corresponding
telluride (1.5 mmol) in 30 cm3 of dry diethyl ether at r.t.
An orange-red precipitate was formed immediately. The
product was washed with ethanol then dried in vaccuo.
Recrystallization from ethanol and chloroform (1:2)
gave an orange crystal of the diiodide (Table 1).
2.2.18. Synthesis of organyltellurium triiodide (33, 34,
35, 36)
The same procedure as for the diiodide was applied to
prepare compounds 33, 34, 35 and 36, but ArTeCN was
used as starting material. All compounds obtained as
orange-red crystals after recrystallization from a mixture
of ethanol and dichloromethane (2:3).
2.2.16. Synthesis of organyltellurium trichloride (25, 26,
27, 28)
Compounds 25Á36 were also prepared by adding
/
thionyl chloride, bromine and iodine to the correspond-
ing ditelluride (i.e., 5, 6, 7 and 8) to afford the
trichloride, tribromide and triiodide in good yields (see
Table 1 for comparison).
25, 26, 27 and 28 were prepared by treating ArTeCN
(1.5 mmol) with thionyl chloride (1.5 mmol) by the same
method for the preparation of the dichloride. Recrys-
tallization of the product from ethanol and chloroform
(1:1) gave a white solid of the corresponding trichloride
(Table 1).
Physical and analytical data for compounds 13Á
/
36
are presented in Table 1.

44
A.Z. Al-Rubaie et al. / Journal of Organometallic Chemistry 673 (2003) 40Á46
/
Scheme 1. Preparative method for compounds 1Á36. Reagents: (i) KTeCN/DMSO (ii) 10% NaOH (iii) Cu/dioxane (iv) SOCl2, Br2 and I2 (v) SOCl2,
/
Br2 and I2 (vi) SOCl2, Br2 and I2.
2.3. Oxidation of diorganyl tellurides with MCPBA
2.4. Oxidation of diorganyltellurium dichlorides with
MCPBA
A typical experimental procedure is as follows. To a
dry CH2Cl2 (5 cm3) solution of diphenacyl telluride
(1.46 mg; 0.40 mmol) was added dropwise a dry CH2Cl2
(3 cm3) solution of m-chloroperbenzoic acid (MCPBA;
70% purity, 1.04 mg, 0.60 mmol) at 0 8C under N2, and
the resulting mixture was stirred for 2 h at 0 8C. The
mixture was poured into saturated aqueous Na2CO3
Similar method described in Section 2.3 was applied
to diorganyltellurium dichlorides (0.40 mmol). Aceto-
phenone, 4-bromoacetophenone, 4-phenylacetophenone
and propiophenone were obtained in 56, 61, 59 and 48%
yields, respectively.
solution (60 cm3) and extracted with CH2Cl2 (30ꢂ
4
/
cm3). The extracts dried over MgSO4 and evaporated to
leave an oily residue which was purified by column
chromatography to afford acetophenone in 64% yield as
the only product.
3. Results and discussion
Four new organotellurocyanates (i.e., C6H5COCH2-
(1),
TeCN
4-BrC6H4COCH2TeCN
(2),
4-
4-Bromoacetophenone, 4-phenylacetophenone and
propiophenone were obtained in 58, 62 and 59% yields,
respectively.
PhC6H4COCH2TeCN (3) and C6H5COCH(CH3)TeCN
(4)) were prepared from the reaction of potassium
tellurocyanate [11] with the appropriate a-bromoketone

A.Z. Al-Rubaie et al. / Journal of Organometallic Chemistry 673 (2003) 40Á
/46
45
Table 2
Some representative IR, 1H-NMR and 13C-NMR data
Compounds IR (cmꢁ1 1H-NMR (d, CDCl3)
)
13C-NMR (d, CDCl3)
13
16
1650s, 530w, 470w,
325m
4.75 (s, 4H, CH2); 7.30Á
/
8.20 (m, 10H, Ar Ã
/
H)
40.4, 128.2, 129.5, 131.8, 136.9, 196.5
1665s, 520w, 470w,
315m
2.10 (d, 6H, CH3); 5.43 (q, 2H, CH); 7.40Á
10H, Ar ÃH)
4.35 (s, 4H, CH2); 7.80 (q, 8H, Ar Ã
2.05 (d, 6H, CH3); 5.40 (q, 2H, CH); 7.30Á
10H, Ar ÃH)
4.31 (s, 4H, CH2); 7.65 (q, 8H, Ar Ã
2.05 (d, 6H, CH3); 5.40 (q, 2H, CH); 7.30Á
10H, Ar ÃH)
4.80 (s, 2H, CH2); 7.35Á
4.50 (s, 2H, CH2); 7.85 (q, 4H, Ar Ã
2.15 (d, 3H, CH3); 5.35 (q, 1H, CH); 7.30Á
Ar ÃH)
4.45 (s, 2H, CH2); 7.65 (q, 4H, Ar Ã
/
8.40 (m,
8.21 (m,
8.20 (m,
10.2, 46.1, 127.0, 127.6, 128.1, 128.7, 136.0, 141.5,
197.6
/
18
20
1690s, 510w, 470w
1660s, 505w, 480w
/
H)
40.0, 128.0, 129.5, 131.0, 132.5, 139.5, 146.5, 188.5
10.3, 42.1, 128.1, 129.3, 132.2, 137.5, 196.5
/
/
22
24
1660s, 505w, 470w
1685m, 530w, 490w
/
H)
41.4, 126.0, 130.2, 132.0, 133.2, 197.5
10.2, 47.4, 128.5, 129.2, 132.0, 137.5, 196.4
/
/
25
26
28
1690s, 480w, 325m
1680s, 475w
1660s, 460w
/
8.20 (m, 5H, Ar Ã
/
H)
41.6, 127.6, 128.5, 131.6, 137.8, 196.5
47.6, 128.3, 129.1, 132.5, 137.5, 196.7
/
H)
/
8.15 (m, 5H, 9.89, 40.9, 127.8, 129.1, 131.8, 137.0, 198.8
/
30
31
35
1655s, 465w
1690s, 465w
1665s, 485w
/
H)
8.40 (m, 9H, Ar Ã
8.40 (m, 9H, Ar Ã
40.2, 127.1, 128.5, 129.0, 129.6, 130.5, 132.7, 139.5,
146.5, 196.8
4.50 (s, 2H, CH2); 7.10Á
/
/
H)
H)
45.5, 126.8, 127.5, 128.1, 128.5, 136.2, 140.8, 145.5,
197.8
40.2, 127.3, 127.8, 128.6, 136.1, 141.2, 145.5, 198.3
4.46 (s, 2H, CH2); 7.21Á
/
/
in dry DMSO solution. Pure compounds were obtained
after one recrystallization as yellow solids in fair yields
It has been known that the tellurides containing
COCH2Ã groups were prepared for the first time by
Ã
/
/
a mild Na2S2O5 reduction of diorganyltellurium dichlor-
ides in a two-phase system [6]. Refluxing compounds 5,
6, 7 and 8 in dry dioxane for 1 h in presence of a
threefold molar excess of activated copper gave com-
pounds 9, 10, 11 and 12 as yellow solids in 67, 77, 74 and
54% yields, respectively. It is worth noting that com-
pounds 9 and 10 have been prepared in 55 and 76%
yields, respectively, by reducing the diphenacyltellurium
dichloride and bis(4-bromophenacyl)tellurium dichlor-
ide in the two-phase system [6]. Thus, we developed a
new route to prepare these tellurides in good yields.
(35Á59%). The IR spectra of these compounds showed
/
low carbonyl absorption, which appeared around 1650
cmꢁ1 as a strong band. Furthermore, compounds 1, 2, 3
and 4 show strong bands at 2210, 2210, 2170 and 2160
cmꢁ1, respectively, which are attributed to n(TeÃ
/CN)
1
[12,13]. In the H-NMR spectra, the expected ratio of
aliphatic to aromatic protons was observed. The meth-
ylene protons (COCH2TeCN) appeared as singlet at
around 4.40 ppm for 1, 2 and 3, while for compound 4
the COCH(CH3)Ã
(see Section 2). 13C-NMR spectra of compounds 1, 2, 3
and 4 revealed the presence of TeÃCN around 118.0
ppm and CO at around 197.0 ppm. These agree well
with literature values [14]. In general, compounds 1Á
/TeCN proton appeared as quartet
The tellurides 9Á
chloride, bromine and iodine to afford dichloride (13Á
16), dibromide (17Á20) and diiodide (21Á24) derivatives,
/12 readily reacted with thionyl
/
/
/
/
/
4
respectively in good yields (Scheme 1). Isolated yields,
melting points, colours and analytical data for com-
are moderately stable at room temperature and are to
handle at room temperature.
pounds 13Á/24 are shown in Table 1. The molar
Treatment of compounds 1, 2, 3 and 4 with ethanolic
sodium hydroxide (10%) is the most obvious way to
prepare the ditellurides 5, 6, 7 and 8, respectively, as
many ditellurides have been prepared by this method
[13b,14]. Compounds 6, 7 and 8 were obtained as red
solids while 5 was obtained as a red semisolid com-
pound. Attempts to solidify 5 were unsuccessful. These
new compounds were obtained in good yields and quite
stable to handle them at room temperature (Scheme 1).
IR and NMR data together with elemental analyses
support the formation of these new compounds.
IR spectra indicate the presence of nCO between 1650
and 1695 cmꢁ1 as a strong band. 13C-NMR spectra
showed the presence of CO signal between 197.2 and
198.5 ppm.
conductance of each compound (13Á
/
24) was examined
over a range of concentration in DMSO solution. In
each case, a non-linear plot of molar conductivity (LM)
against (concentration)1/2 was found to be typical of a
weak electrolyte. All compounds gave appreciable con-
ducting solution at a concentration of 10ꢁ3 M (Table 1).
IR and NMR data for all compounds are presented in
Table 2.
Compounds 1, 2, 3 and 4 and compounds 5, 6, 7 and 8
can be easily converted to the trichloride (25Á
/28), the
tribromide (29Á32) and the triiodide (33Á36) with
/
/
thionyl chloride, bromine and iodine, respectively.
Conductivity measurements in DMSO solution indi-
cated that compounds 25Á/36 are weak electrolytes, and
the values of LM approach 1:1 electrolytes (Table 1).

46
A.Z. Al-Rubaie et al. / Journal of Organometallic Chemistry 673 (2003) 40Á46
/
Table 3
Oxidation of compounds 9Á
16 with MCPBA a
1H- and 13C-NMR data are in good agreement with
the formulation of these compounds (Table 2).
/
When tellurides 9Á/12 and diorganyltellurium dichlor-
Compounds
Products (GLC yield (%))
ides 13Á16 were oxidized with MCPBA in dichloro-
/
9
Acetophenone (64)
methane [17], the corresponding methyl aryl ketones
were obtained in good yields as the only product (Table
3).
Molecular weight determination for selected com-
pounds indicated that these compounds are monomeric
in benzene solution (Table 4).
10
11
12
13
14
15
16
4-Bromoacetophenone (58)
4-Phenylacetophenone (62)
Propiophenone (59)
Acetophenone (56)
4-Bromoacetophenone (61)
4-Phenylacetophenone (59)
Propiophenone (48)
In conclusion, we have shown that tellurides contain-
group can be synthesized indirectly by
a
ing Ã
/
COCH(R)Ã
/
At 0 8C for 2 h.
using this efficient synthetic route. Many types of new
acetylated organotellurium compounds were also pre-
pared by using the corresponding tellurocyante as a
starting material. These new compounds could be used
Table 4
Molecular weight determination for selected compounds
in organic synthesis as they contain a weak telluriumÁ
/
Compounds Molecular weight (Calc.) Molecular weight (Found)
carbon bond.
2
351.65
521.54
523.68
518.08
525.69
777.49
677.89
553.75
353.10
434.99
429.20
500.50
349.93
523.62
523.04
519.95
527.00
774.03
672.69
557.84
358.66
437.85
432.46
500.99
8
10
11
17
22
19
23
25
26
27
32
Acknowledgements
Authors would like to thank Prof. S. Uemura, Kyoto
University, Japan for helpful discussion and for reading
the manuscript.
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580 cmꢁ1 due to nas(TeÃ
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/24 showed two bands in
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is coordinated to the Te atom through its oxygen atom,
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/
O)
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/
/
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/
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/
/O
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