Cyclohexanol → 2-Bromoanthracene

Temperature

155 °C

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).

1. customfitted with a distillation head and receiver
2. temperatureThe mixture was heated until distillate
3. custombegan collecting in the receiver at a pot temperature of about 120° C
4. distillationThe distillation
5. customreached 162° C.
6. temperaturecooled to 100° C.
7. additionpoured into a large beaker
8. additioncontaining methanol (MeOH) (1 L), water (400 mL) and concentrated HCl (200 mL)
9. customThe off-white precipitate was collected on a filter frit (40-60 μm pores)
10. washwashed with water (30 mL) and MeOH (1 L)
11. customair-dried overnight
12. customThe product was dried further under vacuum
13. customto afford 22.4 g (71 percent yield)
14. custom220° C., ΔH=126 Jg−1

ORD record

ord-e26a910be37f41c9a18a18f3e5819bd5

Source dataset

uspto-grants-2008_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07315042B2