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Shriner, R. L.; Fuson, R. C.; Curtin, D. Y.; Morrill, T.
C. The Systematic Identification of Organic Compounds,
6th ed.; John Wiley: New York, 1980; Chapter 6, p. 339.
8. (a) Xia, M.; Chen, Z. Synth. Commun. 1997, 27, 1321; (b)
Xia, M.; Chen, S.; Bates, D. K. J. Org. Chem. 1996, 61,
9289; (c) Drabowicz, J.; Pacholczyk, M. Phosphorus, Sul-
fur 1987, 29, 257; (d) Brownbridge, P.; Jowett, I. C.
Synthesis 1988, 253; (e) Klunder, J. M.; Sharpless, K. B.
J. Org. Chem. 1987, 52, 2598; (f) Fernandez, I.; Khiar,
N.; Llera, J.; Alcudia, F. J. Org. Chem. 1992, 57, 6789;
(g) Solladie, G.; Hutt, J.; Girardin, A. Synthesis 1987,
173; (h) Solladie, G.; Matloubi Moghaddam, F. J. Org.
Chem. 1982, 47, 91.
9. The sulfinate esters were prepared (Refs. 5, 8g,h) as
follows: Sulfinyl chloride was prepared in situ from pow-
dered and dried sodium p-toluenesulfinate (1 g, 5.62
mmol) added in one batch to a solution of thionyl
chloride (2 ml, 28 mmol) in dry benzene (5 ml) at 0°C.
After the completion of the reaction, the excess thionyl
chloride and benzene were evaporated until a green gel
remained. Dry ether (5 ml) was added to the gel and a
white precipitate (NaCl) appeared, the mixture was
cooled to −20°C. Pyridine (1 ml) and phenol (5.62 mmol)
were added and a white precipitate was formed. The
mixture was stirred for 8 h at −20°C, then diluted with
ether and water, and subsequently treated with 5% aq.
citric acid, saturated NaHCO3, 0.25N NaOH and brine
and the organic phase was dried using MgSO4. Evapora-
tion of the solvent gave the aryl p-toluenesulfinates in
good yields. The esters obtained have low mps and must
be used immediately or kept in a refrigerator [IR: 1135
cm−1 (SꢀO); 835 cmꢁ1 (S-O)].
10. General procedure for the thia-Fries rearrangement of
aryl sulfinate esters: 1.5 mmol of the ester and 3 mmol
FeCl3 in (8 ml) dry dichloromethane was used under
nitrogen. FeCl3 was added in one batch and a change in
color was observed immediately. The reaction mixture
was stirred for the required time (see Table 2) at 25°C.
The reaction was diluted with dichloromethane and
water, then 5 ml conc. HCl was added to the reaction
mixture suspended in crushed ice and usually accompa-
nied with a change in color of the organic phase. The
organic phase was washed with water and brine and dried
over MgSO4. The crude product, after evaporation of the
solvent, was crystallized from ethanol and hexane or
purified by column chromatography on silica gel (eluent:
dichloromethane, petroleum ether). Spectral data for
selected compounds: [2-(4-methylphenyl) sulfinyl-4-tert-
butyl phenol (3c)]: mp=140°C; IR (KBr pellet) cm−1
:
3192 (OH, intramolecular hydrogen bonding), 2951, 1015
(SꢀO); 1H NMR (CDCl3): l 9.0 (bs, 1H, OH), 7.9–7.6,
7.1–6.8 (4H, AA%BB% system), 7.6–7.3 (m, 3H, aromatic),
2.5 (s, 3H, Me), 1.4 (s, 9H, t-Bu); 13C NMR (CDCl3): l
167, 158, 143, 142, 140, 130, 125, 123, 122, 119, 34, 31,
21.; [2-(4-methylphenyl)sulfinyl-4-chloro phenol(3b)]:
mp=169°C, IR (KBr pellet) cm−1: 3061 (OH, intramolec-
1
ular hydrogen bonding), 1000 (SꢀO); H NMR (CDCl3):
l 10.1 (bs, 1H, OH), 7.6–7.3, 6.8–6.5 (4H, AA%BB% sys-
tem), 7.2–6.9 (m, 3H, aromatic), 2.2 (s, 3H, Me); 13C
NMR (CDCl3): l 168, 147, 146, 138, 136, 135, 130, 129,
127, 123, 26.
11. Carreno, M. C.; Garcia Ruano, J. L.; Maestro, M. C.;
Martin Carbejas, L. M. Tetrahedron: Asymmetry 1993, 4,
4727.