反応 #345497

反応方程式

anthraquinone

anthracene

2-chloroanthraquinone

hexane methylene chloride

→

desired compound

収率 14.4%

2-Chloroanthracene

収率 14.4%

溶媒

ammonium hydroxide

water

methylene chloride

反応条件

後処理

1. 1
   workup.ADDITIONAfter the addition
2. 2
   温度the stirred mixture was heated gradually over 3 h to 90° C.
3. 3
   温度maintained at 90°-95° C. for 2 h (red color dissipated)
4. 4
   workup.STIRRINGThe reaction mixture was stirred overnight as it
5. 5
   温度cooled to room temperature
6. 6
   workup.STIRRINGstirred for 2 h
7. 7
   ろ過filtered through Celite
8. 8
   その他to remove the excess zinc
9. 9
   洗浄The filter cake was washed with methylene chloride (6×1 L)
10. 10
    その他The methylene chloride layer was separated from the aqueous,
11. 11
    workup.ADDITIONthen treated with 6N hydrochloric acid (3 L)
12. 12
    workup.STIRRINGstirred for 2 h
13. 13
    ろ過A first crop of 2-chloroanthracene was collected by filtration
14. 14
    洗浄washed with water (4×1 L)
15. 15
    その他Vacuum drying
16. 16
    その他afforded a light yellow crystalline product
17. 17
    濃縮The methylene chloride portion of the filtrate was concentrated in vacuo to 10% of its original volume

実験手順

A stirred suspension of 2-chloroanthraquinone (1260 g, 5.19 mol) in concentrated ammonium hydroxide (7.5 L) and water (2.5 L) was warmed to 40° C. Zinc dust (845 g, 12.93 mol) was added in one portion, changing the color to deep red. The mixture was stirred for 45 min at 50° C., then cautiously treated with a second portion of zinc dust (845 g). After the addition, the stirred mixture was heated gradually over 3 h to 90° C., then maintained at 90°-95° C. for 2 h (red color dissipated). TLC analysis (silica gel; hexane:methylene chloride (3:1)) showed complete conversion of the anthraquinone (Rf 0.35) to the desired anthracene (Rf 0.80). The reaction mixture was stirred overnight as it cooled to room temperature. The cooled mixture was treated with methylene chloride (4 L), stirred for 2 h, then filtered through Celite to remove the excess zinc. The filter cake was washed with methylene chloride (6×1 L). The methylene chloride layer was separated from the aqueous, then treated with 6N hydrochloric acid (3 L) and stirred for 2 h. A first crop of 2-chloroanthracene was collected by filtration and washed with water (4×1 L). Vacuum drying afforded a light yellow crystalline product weighing 804.6 g (mp 220°-221° C.). The methylene chloride portion of the filtrate was concentrated in vacuo to 10% of its original volume. This produced an additional 158.5 g of the desired compound for a total yield of 963.1 g (87.2%). NMR (CDCl3) 8.39 (s, 1H), 8.30 (s, 1H), 7.96 (s, 4H), 7.49 (s, 2H), 7.36 (d, J=8.7 Hz, 1H).

出典