Mendeleev Commun., 2006, 16(1), 13–14
The AmtOCs/NMP system was equal in efficiency to ButOK/
NMP (MP yield, 93%; methanol conversion, 94%).‡
Under the same conditions,‡ the ButONa-catalysed reaction
gives 38% methanol conversion (MP yield of 86%), and CsF/
NaOH gives 15% conversion (MP yield of 73%), whereas NaOH
does not catalyse the addition (evidently, due to neutralization
by NMP).
References
1
2
3
E. M. Carreira, W. Lee and R. A. Singer, J. Am. Chem. Soc., 1995, 117,
3649.
(a) L. F. Tietze and J. Gorlitzer, Synthesis, 1997, 877; (b) L. F. Tietze
and J. Gorlitzer, Synlett., 1997, 1049.
4
5
In the KOH/DMSO system, the yield of MP is about 80% at
75% methanol conversion.§
The higher activity of the ButOK/NMP and AmtOCs/NMP
systems is likely due to the specific solvation (complexation) of
the cations by the amide function, which results in an additional
anion desolvation and a capture of propyne and allene as
ligands by the complex cation with their relevant activation.
The complex formation is evidenced by the charge-transfer bands
in the UV spectrum of a solution of ButOK in NMP (283, 543
and 580 nm, bright purple colour) and a high-frequency C=O
stretching shift in the IR spectrum (1683 ® 1693 cm–1) apparently
due to the C=N bond contribution.
(a) O. N. Temkin, G. K. Shestakov, I. V. Kalechits, A. M. Taber,
L. D. Kuprijanova and N. I. Anokhina, Ger. Patent, DD 267629,
C07C, 1989 (Chem. Abstr., 1990, 112, 54986); (b) O. N. Temkin,
G. K. Shestakov, L. D. Kuprianova, A. M. Taber, S. S. Zhukovskij and
V. E. Vasserberg, Ger. Patent, DD 265289, C07C, 1989 (Chem. Abstr.,
1990, 112, 54987).
6
7
8
(a) J. H. Teles, N. Rieber, K. Breuer, D. Demuth, H. Hibst and A. Hagemeyer,
Eur. Patent, EP 0887330, C07C, 1998 (Chem. Abstr., 1999, 130, 83190);
(b) J. H. Teles, N. Rieber, K. Breuer, C. W. Rieker, D. Demuth, H. Hibst
and A. Hagemeyer, Eur. Patent, EP 0887331, C07C, 1998 (Chem. Abstr.,
1999, 130, 83191); (c) J. H. Teles, N. Rieber, K. Breuer, D. Demuth
and H. Hibst, Eur. Patent, EP 0887332, C07C, 1998 (Chem. Abstr.,
1999, 130, 83192).
+
ButO–
OK
...
K
O
OK
N
N
N
Me
Me
Me
Scheme 2
9
Note that no other products, except for MP, are detectable in
the reaction mixture thus indicating that actual selectivity of the
process for both methanol and propyne–allene is close to 100%.
10 J. Schroeder, S. Boeck and K. Ebel, Eur. Patent, EP 0776879, C07C,
1997 (Chem. Abstr., 1998, 127, 81155).
11 (a) J. H. Teles, N. Rieber, K. Breuer, D. Demuth, H. Hibst, H. Etzrodt
and U. Rheude, World Patent, WO 9858894, C07C, 1998 (Chem. Abstr.,
1999, 130, 68148); (b) J. H. Teles, N. Rieber, K. Breuer, D. Demuth,
H. Hibst, H. Etzrodt and U. Rheude, US Patent, US 6211416, C07C,
1999 (Chem. Abstr., 1999, 130, 68148).
†
GLC was performed on a Chrom-4 chromatograph; column, 2400×
×3.5 mm; liquid phase, polyethylene glycol 20000, 10%; solid phase,
Inerton-AW-DMCS, 0.2–0.25 mm; thermal conductivity detector; helium
1
as a carrier gas; column temperature, 65 °C. H NMR spectra were run
12 S. Krill, S. Kretz, V. Hafner and G. Markowz, US Patent, US 6566559,
2001 (Chem. Abstr., 2003, 136, 55543).
on a Bruker DPX-400 (400 MHz) spectrometer. Chemical shift values are
in ppm relative to HMDS. IR spectra were recorded on a Bruker IFS-25
instrument in thin layers.
13 Y. Wang, H. Li, C. Wang and H. Jiang, Chem. Commun., 2004, 1938.
14 B. A. Trofimov, Geteroatomnye proizvodnye atsetilena. Novye poli-
funktsional’nye monomery, reagenty i poluprodukty (Heteroatomic
Derivatives of Acetylene. New Polyfunctional Monomers, Reagents
and Intermediates), Nauka, Moscow, 1981 (in Russian).
15 B. A. Trofimov and S. V. Amosova, Divinilsul’fid i ego proizvodnye
(Divinyl Sulfide and Its Derivatives), Nauka, Novosibirsk, 1983 (in
Russian).
16 B. A. Trofimov and A. I. Mikhaleva, N-Vinilpirroly (N-Vinylpyrroles),
Nauka, Novosibirsk, 1984 (in Russian).
18 B. A. Trofimov, in Modern Problems of Organic Chemistry, eds.
A. A. Potechin, R. R. Kostikov and M. S. Baird, VVM, St. Petersburg,
2004, vol. 14, p. 121.
19 J. Henkelmann, H. Becker, J. Aiscar, B. A. Trofimov, N. K. Gusarova
and L. A. Oparina, US Patent, US 6504064, C07C, 2002 (Chem. Abstr.,
2003, 136, 69592).
Commercial propyne (98%) and ButOK (Aldrich) were employed.
AmtOCs was kindly presented by Professor L. Brandsma (Utrecht
University, the Netherlands). The propyne–allene mixture (4:1) was
prepared by dehydrochlorination of allyl chloride in the KOH/DMSO
system.
Typical procedure. ButOK (2.8 g, 25 mmol) was dissolved in NMP
(50 ml) and placed in a four-neck flask (100 ml) equipped with a bubbler,
a thermometer, a dropping funnel and a high performance reflux con-
denser connected with two coil traps. The solution was heated to 120 °C
with stirring using a magnetic stirrer. Methanol (4.8 g, 150 mmol) was added
dropwise at a feeding rate of 1 ml h–1 and the propyne–allene mixture
(~1 dm3 h–1) was fed continuously into the catalytic solution. 2-Methoxy-
propene and methanol, partially removed with a flow of gases, were
collected in a downstream cooled trap (–5 °C). Unused propyne and
allene were collected in the second trap cooled to –60 °C and then
returned to the reaction flask. After 12 h, the condensate consisting of
MP (9.2 g, 128 mmol) and methanol (0.6 g, 18 mmol) was collected.
The yield of MP based on methanol consumed was 97%. Distillation of
the mixture gives the pure target product.
2-Methoxypropene: 1H NMR (CDCl3) d: 3.76 (d, 2H, CH2=, 2J 2.0 Hz),
3.43 (s, 3H, OMe), 1.72 (s, 3H, Me). IR (CDCl3, n/cm–1): 650, 734, 802,
822, 909, 935, 993, 1023, 1085, 1197, 1285, 1371, 1395, 1451, 1607,
1660, 2845, 2957, 3000, 3122.
‡
Analogously, from methanol (4.8 g, 150 mmol) and propyne in the
presence of AmtOCs (11.0 g, 50 mmol) in NMP (50 ml) the condensate
consisting of MP (9.4 g, 131 mmol, 87% yield) and methanol (0.3 g,
9 mmol) was collected. The total yield of MP based on methanol con-
sumed was 93%.
§
KOH (2.8 g, 50 mmol), methanol (1.6 g, 50 mmol) and DMSO (50 ml)
were placed in a flask and saturated with the propyne–allene mixture
at room temperature. The mixture was heated to 100 °C, and methanol
(1.6 g, 50 mmol) in DMSO (2 ml) was added dropwise while propyne–
allene mixture was bubbled for 3 h. The condensate contained 4.3 g
(60 mmol) of MP and 0.8 g (25 mmol) of methanol. The yield of MP
was 80%, the conversion of methanol was 75%.
Received: 9th June 2005; Com. 05/2529
14 Mendeleev Commun. 2006