3622
K. V. Kilway, J. S. Siegel / Tetrahedron 57 /2001) 3615±3627
hydride then sodium. Benzene was distilled and then
sodium. Tetrahydrofuran was distilled either from sodium
or lithium aluminum hydride.
re¯ux. Water -25 mL) was added to the solution. The pH
was tested of the solution periodically. When the solution
was found to be acidic, sodium hydroxide was added -total
amount: 0.36 g, 9.0 mmol). The reaction progress was also
monitored via thin layer chromatography -1:9 chloroform/
hexanes) until the spot for the starting material disappeared.
The reaction mixture was cooled, neutralized with HCl, and
poured onto ice. The product was isolated after normal
aqueous workup to yield a white solid -0.20 g, 0.8 mmol,
1,4-Dimethoxytetraethylbenzene -29) was synthesized
according to the previously described procedure from
2,3,5,6-tetraethylquinone, which was reduced to the corre-
sponding 1,4-dihydroxy-2,3,5,6-tetraethylbenzene, and then
methylated toproduce 29.25 1,4-Bis-chloromethyl)-2,3,5,6-
tetraethylbenzene -3) was synthesized by Friedel±Crafts
acylation of 1,2,4-triethylbenzene, Wolff±Kishner reduction
to produce 1,2,4,5-tetraethylbenzene and chloromethylation to
yield 3. 1,4-Bis-methoxymethyl)-2,3,5,6-tetraethylbenzene
-6) was produced by the methanolysis of 3. 1,4-Dineohexyl-
2,3,5,6-tetraethylbenzene -23) was synthesized by succes-
sive alkylation of benzene with 3,3-dimethylbutyryl chlor-
ide followed by Wolff±Kishner reduction and exhaustive
ethylation of the resulting 1,4-dineohexylbenzene. 1,4-
Bis-4,4-dimethyl-3-oxopentyl)-2,3,5,6-tetraethylbenzene
-21) was synthesized by reacting the trimethylsilyl-
protected enolate of pinacolone with 3 using titanium tetra-
chloride as the catalyst. Compounds 13,21f 15,21d 17,21d,21g
and 1921f were synthesized using previously reported
methodologies.
1
47%) mp 158±1598C; H NMR -CDCl3, 250 MHz) d 1.26
3
3
-9H, t, J7.5 Hz), 2.95 -6H, q, J7.5 Hz), 4.78 -6H, s);
13C {1H} NMR -acetone-d6, 62.9 MHz) d 17.3, 23.05, 58.7,
135.9, 144.2; IR -KBr) 3500±3050 -bs) cm21; Exact Mass
-EI) 252.1732; calcd for C15H24O3 -M1) 252.1725.
4.1.4. 1,4-Bis0methylthiomethyl)-2,3,5,6-tetraethylben-
zene 010). Compound 3 -0.50 g, 1.8 mmol) was dissolved
in acetone -20 mL) and heated to re¯ux. A solution of
sodium thiomethoxide -0.37 g, 5.2 mmol) in water
-10 mL) was added. The solution was re¯uxed overnight.
After 15 h, the reaction was cooled and poured onto water/
ice and the resulting white solid was ®ltered and washed
with water yielding 10 -0.461 g, 1.5 mmol, 85%): mp
1
135±1368C; H NMR -CDCl3, 360 MHz) d 1.22 -12H, t,
3J7.6 Hz), 2.19 -6H, s), 2.77 -8H, q, 3J7.6 Hz), 3.74 -4H,
s); 13C{1H} NMR -CDCl3, 75 MHz) d 15.9, 16.8, 22.4, 33.5,
132.6, 139.3; Exact Mass -EI) 310.1789; calcd for C18H30S2
-M1) 310.1779.
4.1.1. 1,3,5-Tris0chloromethyl)-2,4,6-triethylbenzene 05).
Compound 5 was synthesized according to an adapted
procedure of Gambarova for chloromethylation of alkyl-
benzenes.45±49 1,3,5-Triethylbenzene -1.50 g, 9.2 mmol)
was dissolved in dry dichloromethane -35 mL) at 08C. To
the swirling solution, chloromethyl methyl ether -6.79 g,
9 mL, 84.3 mmol) was added. Then, stannic chloride
-21.6 g, 9.71 mL, 83 mmol) was added slowly to the
precooled, swirling solution. After three h at 0±58C, the
reaction was quenched with ice water and stirred until
the color changed from brown to white oil. This was then
extracted with chloroform, dried with anhydrous sodium
sulfate, and evaporated yielding a cream solid, which was
recrystallized from ethanol. -2.12 g, 6.85 mmol, 77%) mp
1448C; 1H NMR -CDCl3, 360 MHz) d 1.31 -9H, t,
3J7.6 Hz), 2.92 -6H, q, 3J7.6 Hz), 4.69 -s, 6H);
13C{1H} NMR -CDCl3, 75 MHz) d 16.0, 22.6, 40.6,
132.6, 144.9; Exact Mass -EI) 306.0716; calcd for
C15H21Cl3 -M1) 306.0709.
4.1.5.
1,3,5-Tris0methylthiomethyl)-2,4,6-triethylben-
zene 011). Compound 5 -0.51 g, 1.7 mmol) was dissolved
in acetone -45 mL) and heated to re¯ux. A solution of
sodium thiomethoxide -0.52 g, 7.4 mmol) in water -5 mL)
was added. The solution was re¯uxed overnight. After 15 h,
the reaction was cooled and poured onto water/ice. The
resulting white solid was ®ltered and washed with water
1
yielding 11 -0.47 g, 1.4, 81%) mp 128±1298C; H NMR
3
-CDCl3, 250 MHz) d 1.27 -9H, t, J7.5 Hz), 2.14 -9H,
3
s), 2.81 -6H, q, J7.5 Hz), 3.75 -6H, s); 13C{1H} NMR
-CDCl3 62.9 MHz) d 16.1, 16.6, 22.9, 33.0, 131.6, 142.2;
Exact Mass -EI) 342.1515; calcd for C18H30S3 -M1)
342.1510.
4.1.6. 1,4-Bis0cyanomethyl)-2,3,5,6-tetraethylbenzene 012).
1,4-Bis-chloromethyl)-2,3,5,6-tetraethylbenzene -1.0 g,
3.5 mmol) was dissolved in acetone -40 mL) and heated to
re¯ux. Potassium cyanide -0.68 g, 10.5 mmol) was added.
Then, water -,15 mL) was slowly added until the solution
became turbid. Acetone -2 mL) was added, and the reaction
was left to re¯ux overnight. After 15 h, the solution was
poured onto ice water -100 mL) and the product precipitated
out as a white powder. This solution was ®ltered yielding 12
-0.84 g, 3.1 mmol, 89%): mp 197±1998C; 1H NMR -CDCl3,
360 MHz) d 1.22 -12H, t, 3J7.6 Hz), 2.73 -8H, q,
3J7.6 Hz), 3.69 -4H, s); 13C{1H} NMR -CDCl3,
75 MHz) d 14.9, 17.7, 22.9, 118.3, 127.7, 139.4; IR -KBr)
2238 cm21; Exact Mass -EI) 268.1940; calcd for C18H24N2
-M1) 268.1944.
4.1.2. 1,3,5-Tris0methoxymethyl)-2,4,6-triethylbenzene
07). 1,3,5-Tris-chloromethyl)-2,4,6-triethylbenzene -0.51 g,
1.7 mmol) was dissolved in 45 mL of methanol and heated
to re¯ux. A solution of sodium hydroxide -0.30 g,
7.5 mmol) in water -,35 mL) was added. The reaction
mixture was re¯uxed for 15 h. After which, the reaction
was cooled and poured onto water/ice. The resulting white
solid was ®ltered and washed with water yielding 7 -0.05 g,
0.17 mmol, 10%): mp 83±848C; 1H NMR -CDCl3,
250 MHz) d 1.19 -9H, t, 3J7.5 Hz), 2.93 -6H, q,
3J7.5 Hz), 3.42 -9H, s), 4.45 -6H, s); 13C{1H} NMR
-CDCl3 62.9 MHz) d 16.7, 23.0, 58.5, 66.9, 132.2, 145.2;
Exact Mass -EI) 294.2195; calcd for C18H30O3 -M1)
294.2195.
4.1.7. 1,3,5-Tris0cyanomethyl)-2,4,6-triethylbenzene 013).
Compound 5 -0.70 g, 2.3 mmol) was dissolved in acetone
-60 mL) and heated tore¯ux. Sdoium cyanide -0.50 g,
10.2 mmol) was added. Then, 25 mL of water was added
4.1.3. 1,3,5-Tris0hydroxymethyl)-2,4,6-triethylbenzene
09). 1,3,5-Tris-chloromethyl-2,4,6-triethylbenzene -0.51 g,
1.7 mmol) was dissolved in acetone -50 mL) and heated to