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M. Bonanni et al.
LETTER
to render the synthesis reliable when extended to a
multigram scale.
(12) General Procedure for Quaternization under
Conventional Heating
AB system, J = 11.9 Hz, 2 H), 4.42 (B part of an AB system,
J = 11.9 Hz, 2 H), 4.24 (br s, 2 H), 3.85 (dd, J = 13.5, 5.6 Hz,
2 H), 3.71 (dd, J = 13.5, 2.6 Hz, 2 H). 13C NMR (50 MHz,
CDCl3): d = 135.9 (s, 2 C), 133.3 (d, 4 C), 131.0 (d, 2 C),
129.4 (d, 4 C), 128.5 (d, 4 C), 128.3 (d, 2 C), 127.9 (d, 4 C),
126.6 (s, 2 C), 119.9 (q, 2 C, CF3, J = 319.9 Hz), 80.2 (d, 2
C), 72.3 (t, 2 C), 66.9 (t, 2 C), 60.8 (t, 2 C). 19F NMR (188
MHz, acetone-d6,): d = –79.9 (s). IR (CDCl3): 3090 (w),
3068 (m), 3034 (m), 2923 (w), 2872 (w), 2260 (m), 1497
(m), 1456 (s), 1350 (s), 1199 (s), 1134 (s), 1059 (s) cm–1.
MS: m/z (%) = 464 (0.4), 160 (9), 120 (19), 91 (100), 69 (46),
41 (52). Anal. Calcd for C34H34F6N2O6S2: C, 54.83; H, 4.60;
N, 3.76. Found: C, 54.82; H, 4.86; N, 3.86. [a]D23 +0.9 (c
1.00, CH2Cl2).
In a round-bottom flask the pyrrolidinediol 14 and alkyl or
benzyl bromide (1.5 equiv) were suspended in MeCN. The
mixture was heated at 90 °C until disappearance of the
starting material (TLC control). The reaction mixture was
cooled at 0 °C, and Et2O was added to crystallize the pure
product as a white solid.
General Procedure for Quaternization under Microwave
Heating
In a microwave reactor, the pyrrolidinediol 14 and alkyl or
benzyl bromide (1.5 equiv) were suspended in MeCN. The
reaction was carried out at 90 °C, 150 W for 10 min (TLC
control), then the reaction mixture was cooled to 0 °C, and
the pure product crystallizes as a white solid.
(13) Fowler, P. A.; Haines, A. H.; Taylor, R. J. K.; Chrystal,
E. J. T.; Gravestock, M. B. J. Chem. Soc., Perkin Trans. 1
1993, 1003.
(21) Data for Ionic Liquid 12
Pale yellow viscous liquid. 1H NMR (400 MHz, CDCl3): d =
7.51–7.41 (m, 5 H), 4.66–4.53 (m, 4 H), 4.17 (br s, 1 H), 4.09
(dd, J = 13.1, 4.0 Hz, 1 H), 3.98 (br s, 1 H), 3.79 (d, J = 12.8
Hz, 1 H), 3.73 (dd, J = 12.8, 4.0 Hz, 1 H), 3.37 (d, J = 13.1
Hz, 1 H), 3.30–3.15 (m, 2 H), 1.95–1.84 (m, 2 H), 1.32–1.25
(m, 18 H), 0.87 (t, J = 6.8 Hz, 3 H). 13C NMR (50 MHz,
CDCl3): d = 132.1 (d, 2 C), 130.9 (d, 1 C), 129.4 (d, 2 C),
127.4 (s, 1 C), 119.5 (q, 2 C, CF3, J = 318.7 Hz), 75.8 (d, 1
C), 75.5 (d, 1 C), 68.6 (t, 1 C), 67.7 (t, 1 C), 66.9 (t, 1 C), 63.8
(t, 1 C), 31.9 (t, 1 C), 29.6 (t, 2 C), 29.5 (t, 1 C), 29.4 (t, 1 C),
29.3 (t, 1 C), 29.0 (t, 1 C), 26.2 (t, 1 C), 23.7 (t, 1 C), 22.8 (t,
1 C), 14.2 (q, 1 C). 19F NMR (188 MHz, acetone-d6): d =
–79.8 (s, 6 F). IR (CHCl3): 3507 (m), 3033 (w), 2927 (m),
2855 (w), 1457 (w), 1349 (s), 1192 (s), 1133 (m), 1059 (m)
cm–1. MS: m/z (%) = 362 (35), 288 (12), 270 (11), 206 (6),
193 (7), 134 (5), 116 (100), 91 (45), 69 (11), 55 (15). Anal.
Calcd for C25H40F6N2O6S2: C, 46.72; H, 6.27; N, 4.36.
Found: C, 46.70; H, 6.55; N, 4.35. [a]D22 –5.1 (c 0.985,
MeOH).
(14) (a) Dubreil, D.; Cleopax, J.; Loupy, A. Carbohydr. Res.
1994, 252, 149. (b) Ikemoto, N.; Schreiber, S. L. J. Am.
Chem. Soc. 1992, 114, 2524.
(15) Crystal Data for 1
MW = 364.3, trigonal, space group P31, Z = 3, Dc = 1.46,
a = b = 10.686 (1) Å, c = 12.580 (1) Å, a = b = 90°,
g = 120°, V = 1244.1 (2) Å3. The X-ray CIF file for this
structure has been deposited at the Cambridge
Crystallographic Data Centre (CCDC), deposition number
710820.
(16) Crystal Data for 5
MW = 544.5, orthorhombic, space group P212121, Z = 4,
Dc = 1.37, a = 9.767 (1) Å, b = 9.805 (1) Å, c = 27.605 (1)
Å, a = b = g = 90°, V = 2643.6 (4) Å3. The X-ray CIF file for
this structure has been deposited at the CCDC, deposition
number 710821.
(22) Data for Ionic Liquid 4
Pale yellow solid; mp 50–53 °C. 1H NMR (200 MHz,
CD3OD): d = 7.63–7.50 (m, 10 H), 4.89 (br s, 2 H), 4.71 (br
s, 2 H), 4.32–4.24 (m, 2 H), 3.87 (dd, J = 12.5, 5.1 Hz, 2 H),
3.60 (dd, J = 13.2, 1.5 Hz, 2 H). 13C NMR (50 MHz, CDCl3):
d = 133.2 (d, 4 C), 131.1 (d, 2 C), 129.5 (d, 4 C), 127.1 (s, 2
C), 119.6 (q, 2 C, CF3, J = 320.5 Hz), 76.1 (d, 2 C), 67.4 (t,
2 C), 63.3 (t, 2 C). 19F NMR (188 MHz, acetone-d6): d =
–79.9 (s). IR (CH2Cl2): 3593 (w), 3502 (m), 3059 (w), 3032
(w), 2923 (w), 1494 (w), 1457 (w), 1351 (s), 1199 (s), 1134
(m), 1060 (m) cm–1. MS: m/z (%) = 284 (22), 210 (7), 193
(6), 133 (11), 120 (11), 91 (100), 65 (25), 51 (7). Anal. Calcd
for C20H22F6N2O6S2: C, 42.55; H, 3.93; N, 4.96. Found: C,
42.36; H, 4.12; N, 4.95. [a]D23 –24.5 (c 1.01, CH2Cl2).
(23) (a) Wasserscheid, P.; Bösmann, A.; Bolm, C. Chem.
Commun. 2002, 200. (b) Levillain, J.; Dubant, G.;
(17) Anion Exchange (Procedure A)
In a round-bottom flask the pyrrolidinium bromide 1 or 5
(1–5 mmol) were suspended in H2O–EtOAc (1:1), then the
appropriate potassium or lithium salt was added. After 5 min
the two phases became limpid, and the reaction was finished.
The organic phase was separated and dried with anhyd
Na2SO4. Solvent evaporation gave the pure product.
(18) Upon addition of a slight excess of AgNO3 the solution
became yellow due to formation of Ag2CrO4.
(19) Anion Exchange (Procedure B)
In a round-bottom flask the pyrrolidinium bromide 9 was
suspended in H2O, then the appropriate potassium or lithium
salt was added. The mixture was left to react overnight at r.t.,
and the formation of a pale yellow oil, insoluble in H2O, was
observed. Ethyl acetate was then added. The organic phase
was separated and dried with anhyd Na2SO4. Solvent
evaporation gave the pure product.
Abrunhosa, I.; Gulea, M.; Gaumont, A.-C. Chem. Commun.
2003, 2914. (c) Clavier, H.; Boulanger, L.; Audic, N.;
Toupet, L.; Mauduit, M.; Guillemin, J.-C. Chem. Commun.
2004, 1224. (d) Patil, M. L.; Rao, C. V. L.; Yonezawa, K.;
Takizawa, S.; Onitsuka, K.; Sasai, H. Org. Lett. 2006, 8,
227. (e) Jurćíik, V.; Gilani, M.; Wilhem, R. Eur. J. Org.
Chem. 2006, 5103. (f) Kumer, V.; Olsen, C. E.; Schäffer, S.
J. C.; Parmar, V. S.; Malhotra, S. V. Org. Lett. 2007, 9, 3905.
(20) Data for Ionic Liquid 8
Pale yellow viscous liquid. 1H NMR (400 MHz, CDCl3): d =
7.47–7.43 (m, 10 H), 7.35–7.32 (m, 6 H), 7.22–7.19 (m, 4
H), 4.73 (A part of an AB system, J = 13.1 Hz, 2 H), 4.63 (B
part of an AB system, J = 13.1 Hz, 2 H), 4.46 (A part of an
Synlett 2009, No. 5, 747–750 © Thieme Stuttgart · New York