Unusually facile dissociation of benzene by ruthenium metal

g, 5.0 mmol) was added to a suspension of NaH (60% oil dispersion, 0.22 g, 5.5 mmol) in dry THF (10 mL) under N2.After the mixture was stirred for 20 min, l-(2-(/?-toluenesulfonoxy)ethoxy)anthracene-9,10- dione (1.06 g, 2.5 mmol) was added as a solid.The reaction mixture was brought to reflux temperature and stirred for 18 h.The mixture was cooled and concentrated in vacuo.The residue was added to H20 (25 mL) and extracted with CHC13 (2 X 25 mL).The combined organic phases were washed with brine (10 mL), dried (MgS04), and concen- trated in vacuo.Column chromatography (90 g silica gell 60, 60%CHCl3/hexanes-2% MeOH/CHCl3) followed by recrystallization (EtOH) gave 5 (160 mg, 14%) as a yellow powder: mp 48-49 °C; NMR (CDC13) 3.33 (s, 3 H, CH3), 3.55-4.05(m, 18 H, CH2's), 4.27 (t, 2 H, CH2OAr), 7.22-8.22(m, 7 H, Ar); IR (KBr) 1670, 1590, 1320, 1270, 1150, 1140, 1105, 990, 720 cm"1.Anal.Caled for C25H30O8; C, 65.48; H, 6.61.Found: C, 66.64; H, 6.34.l,8-Bis(I-oxaanthracene-9,10-dione)-3,6-dioxaoctane (6).Method A.Compound 6 was prepared from the potassium salt of 1-hydroxy- anthraquinone (2.62 g, 0.01 mol), l,2-bis(2-iodoethoxy)ethane (1.85 g, 0.005 mol), 18-crown-6 (2.64 g, 0.01 mol), and CH3CN (30 mL) by a method analogous to that for the preparation of 7 (see procedure below).Column chromatography (silica gel 60, 2% MeOH/CHCl3) followed by recrystallization (2-butanone) gave 6 (0.85 g, 30%) as a yellow powder: mp 173-175 °C; lH NMR (CDC13) 3.90, 4.03, and 4.30 (s, t, and t, 12 H, CH/s), 7.24-8.24ppm (m, 14 H, Ar); IR (KBr) 1670, 1590, 1325, 1275,715 cm"1.Anal.Caled for C34H2608: C, 72.58; H, 4.67.Found: C, 72.48; , 4.71.Method B. Triethylene glycol (3.75 g, 25 mmol) was slowly added to a vigorously stirred suspension of NaH (60% oil dispersion, 2.7 g, 68 mmol) in dry THF (40 mL) under N2.After the mixture was stirred for 45 min, 1-chloroanthraquinone (12.13 g, 50 mmol) was added as a solid, and the flask was rinsed with dry THF (20 mL).The reaction mixture was brought to reflux temperature and vigorously stirred for 6 h.The mixture was cooled and concentrated in vacuo.The residue was added to H20 (300 mL) and extracted with CHC13 (300 mL then 100 mL).The combined organic phases were washed with brine (100 mL), dried (MgS04), and concentrated in vacuo.Two recrystallizations (2-butanone) gave 6 (9.3 g, 66%) as a yellow powder (mp 146-148 °C solidifies and remelts at 175-177 °C).An analytically pure sample was obtained by passing 1 g of sample through a column of silica gel 60 (20 g, 2% MeOH/CHCl3) followed by recrystallization (CH3CN).Approximately 0.97 g of sample was recovered (mp 170-173 °C) which had physical properties identical with those reported above.(Hydroxymethyl)-15-crown-5 was prepared as previously described14 ( 14) Dishong, D. M.; Diamond, C.