Syntheses of 1 - Bromo - , 1 - Chloro - 4 - Nitoro - , and 1 - Bromo - 4 - Nitoro - Anthraquinones

摘要

(1) 1-Bromo-anthraquinone (I) m.p. 178~182℃, 1.4g (yield 37.5%) was prepared from potassium anthraquinone-l-sulphonate 6g, bromine 5g and water 24c.c. in a sealed tube at 190℃ for 6 hours. This was recrystallised from acetic acid to the yel1ow orange needle, m.p. 186~187℃. Also (I) m.p. 184~185℃, 9.6g (yield 81.4%) was prepared from l-chloro-anthraquinone 10g, bromine 12.5g and cupric chloride 0.3g in nitrobenzene 75g at boiling for 24 hours. The yield of the latter methode was greater than that of the former. It was found that anthraquinone was easily obtained by the reaction of (I) with glycerol and potassium carbonate. (2) 1-Chloro-4-nitro-anthraquinone (II) m.p. 228~235℃, 4.7g (yield 39.6%) was prepared from l-chloro-anthaquinone 10g by nitration with conc. H2SO4 100g and conc. HNO3 (D=1.410) 3.2g at 5~10℃ for 5 hours. After the several recrystallisation the yellow needle m.p. 258~259℃ was obtained. (3) 1-Bromo-4-nitro-anthraquinone (III) m.p. 222~247℃, 4.9g (yield 42.2%) was prepared from (I) 10g by nitration with conc. H2SO4 90g and conc. HNO3 (D = 1.410) 3g at 5~10℃ for 5 hours. The melting point of pure (III) was 254~255℃. This compound was determined by nitrogene-analysis, because the melting point of (III) had been unknown. Also (III) m.p. 246~249℃, obtained by the new course from (II), bromine and cupric chloride, was proved to be identical with the pure (III). when measured by mixed melting point methode.