1,2,3-Dithiazolyl and 1,2,35-Dithiadiazolyl Radicals as Spin-Bearing ...

the heat source was removed and the reaction mixture was allowed to cool to room
temperature. The solution was diluted with 50 mL d.i. H 2 O and extracted with 3 x 100
mL CH 2 Cl 2 . The combined extracts were dried with Na 2 SO 4 and evaporated to dryness
to yield the title compound as a bright orange powder (0.8139 g, 4.006 mmol) 52%,
which was used without further purification. ν max (KBr)/cm −1 :
3050(w), 1714(m),
1687(s), 1613(m), 1585(m), 1570(m), 1513(s), 1451(m), 1354(s), 1276(s), 1242(s),
1153(w), 1100(w), 1040(w), 979(m), 923(w), 897(w), 881(w), 823(m), 775(s), 764(s),
730(w), 888(w), 656(w), 594(m), 533(m), 506(m), 460(w). 1 H NMR (300 MHz, DMSOd6):
δ 8.67 (s, 1H), δ 8.02 (dd, J = 0.9, 6.6 Hz, 1H), δ 7.91-7.87 (dt, J = 1.5, 6.0 Hz, 1H),
), δ = 7.80 (dt, J = 0.9, 4.8 Hz, 1H), δ = 7.77 (dt, J = 1.8, 7.2 Hz, 1H).
3,4-Dioxo-3,4-dihydronaphthalen-2-aminium chloride (V-12).
Pd/C (10 mg) was
added to a solution of V-11 (0.7890g 3.884 mmol) in bubble de-gassed MeOH (80 mL).
A balloon was fitted to the middle neck of a three neck flask and the system was flushed
with H 2 three times. The balloon was then inflated once more with H 2 and the system was
sealed. The reaction mixture was stirred for 1h at room temperature. The red solution
was then filtered to remove the Pd/C and 5 mL of conc. HCl was added and stirred
overnight. The MeOH was then rotary-evaporated to afford the title compound as a dark
red powder (0.5701 g, 3.029 mmol) 78% yield. Used without further purification. ν max
(KBr)/cm −1 : 3057(s, broad), 2582(w), 1736(m), 1642(s), 1611(m), 1592(s), 1558(s),
1509(s), 1473(s), 1396(s), 1361(w), 1339(w), 1260(m), 1228(m), 1195(m), 1104(w),
1071(s), 1023(s), 964(m), 918(m), 871(m), 839(m), 766(s), 737(s), 713(m), 680(w),
648(w), 605(w), 548(m), 443(m).
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