Cyclohexanol → 2-Bromoanthracene

Participants

Reaction Conditions

Reaction Steps

2-bromoanthraquinone (Formula XII, 35.2 g) was added to a 3-L, 3-necked flask fitted with a distillation head and receiver. The system was put under N2 and charged with cyclohexanol (1 L), and Al(O-sec-Bu)3 (375 mL). The mixture was heated until distillate began collecting in the receiver at a pot temperature of about 120° C. The distillation was continued until the pot temperature reached 162° C., and then cooled to 155° C. The reaction was stirred at 155° C. over 48 h, then cooled to 100° C. and poured into a large beaker containing methanol (MeOH) (1 L), water (400 mL) and concentrated HCl (200 mL). The off-white precipitate was collected on a filter frit (40-60 μm pores), washed with water (30 mL) and MeOH (1 L), and air-dried overnight. The product was dried further under vacuum to afford 22.4 g (71 percent yield). DSC data (scanned at 20° C./min): peak temp 220° C., ΔH=126 Jg−1. IR (KBr, strong abs only): 892, 741, 474 cm−1. 1H NMR (500 MHz, d6-Me2SO): δ 7.56 (m, 6 lines, 6-H, 8-H), 7.60 (dd, J=2.0 9.0 Hz, 7-H), 8.09 (m, 1-H, 3-H, 4-H), 8.39 (‘d’, J=1 Hz, 9-H), 8.57 (s, 5-H), 8.63 (s, 10-H).

Provenance & Evidence