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★ nealu(金币+1,VIP+0):谢谢应助! 3-31 15:28
在OS上有一片文章,你可以看看.
对羟基苯甲酸乙酯的氯化.
Ethyl 3,5-dichloro-4-hydroxybenzoate. A tared 2-l. round-bottomed flask is equipped with an
efficient reflux condenser connected through a calcium chloride drying tube to a gas-absorption trap,
and is set up on a steam bath in a hood. In the flask are placed 250 g. (1.5 moles) of ethyl 4-
hydroxybenzoate (Note 1) and 444 g. (266 ml., 3.3 moles) of sulfuryl chloride. The mixture is warmed
on the steam bath (gently at first) until gas is no longer evolved (about 1 hour). Then 50 ml. of sulfuryl
chloride is added to the reaction flask, and the warming is continued until gas is no longer evolved. This
entire chlorination procedure requires about 1.5 hours. The excess sulfuryl chloride is then removed by
attaching a water pump through an empty safety flask to the reaction flask and warming on the steam
bath until no evidence of vapor can be detected above the white solid in the reaction flask. The residue
in the flask should weigh about 350 g. (Note 2). Recrystallization from a mixture of 600 ml. of ethanol
and 140 ml. of water gives 315–334 g. (83–88%) of ethyl 3,5-dichloro-4-hydroxybenzoate hydrate
(Note 3) melting at 110–114° with decomposition.
http://www.orgsyn.org/orgsyn/pdfs/CV3P0267.pdf
[ Last edited by TJFWAL on 2009-3-30 at 19:01 ] |
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