10-Methyl-9,10-dihydroacridine (3c) behaves similarly to compound 3b. On the basis of this data the
place of the 1,3-benzodithiole 1 in the known series of hydride mobility [6] can be determined as 3c>3b>1>3a.
The reaction of perchlorate 4 with substances 3b and 3c takes place at 80oC over 1 h. When acetonitrile or acetic
acid are used as solvent in the reaction of compounds 4 and 3b only traces of the 1,3-benzodithiole 1 were
identified by 1H NMR spectroscopy.
According to known data [7] the reaction of the 4-phenyl-1,3-dithiolium ion with 1,3,5-cycloheptatriene
is accompanied by formation of a mixture of 4-phenyl-1,3-dithiolium and tropylium perchlorates. We have
shown, for the first time, that the 4-aryl-1,3-dithiolium perchlorates 5a-c are reduced by compound 3c to give the
4-aryl-1,3-dithioles 6a-c in 58, 62, and 58% yields respectively. The 10-methyl-9,10-dihydroacridinium
perchlorate 7 is formed in close to quantitative yield.
S
THF
80oC
R
S
S
+
3c
R
+
+
S
–
ClO4
H
5a–c
6a–c
+
+
N
–
ClO4
Me
7
5,6 a R = H, b R = Br, c R = Cl
The 1H NMR spectra were recorded on a Mercury 300 (300 MHz) instrument using CDCl3 with HMDS
as internal standard. Mass spectra were taken on an HP 6890/MSD 5973 instrument.
1
4-Phenyl-1,3-dithiole (6a). Mp 45-46°C (mp 45-48°C [8]). H NMR spectrum, δ, ppm: 4.47 (2H, s,
CH2); 6.26 (1H, s, CH, Het); 7.23-7.41 (5H, m, C6H5).
1
4-(4-Bromophenyl)-1,3-dithiole (6b). Mp 95-96°C. H NMR spectrum, δ, ppm (J, Hz): 4.50 (2H, s,
CH2); 6.29 (1H, s, CH, Het); 7.20 (2H, d, J =8.4, Ar); 7.37 (2H, d, J = 8.4, Ar). Mass spectrum, m/z (Irel, %):
259 [M]+ (100), 258 [M-1]+ (97), 212 (18), 179 (3), 89 (52), 76 (5).
1
4-(4-Chlorophenyl)-1,3-dithiole (6c). Mp 69-71oC. H NMR Spectrum, δ, ppm (J, Hz): 4.50 (2H, s,
CH2); 6.27 (1H, s, CH, Het); 7.22 (2H, d, J = 8.7, Ar); 7.27 (2H, d, J = 8.7, Ar). Mass spectrum, m/z (Irel, %):
214 [M]+ (100), 213 [M-1]+ (97), 179 (10), 168 (34), 89 (32), 76 (23).
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4.
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6
L. P. Yunnikova, Zh. Org. Khim., 31, 76 (1995).
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7
8.
A. Takamizawa and K. Hirai, Chem. Pham. Bull., 17, 1931 (1969).
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