how to refine but-2-ynoic acid
i am synthesising this chemicasl but-2-ynoic aicd .
this chemical have three steps :
the first : 3-methylpyrazole -5-one
the second :44-dibromo-3-methylpyrazoble-5-one
the third : but-2-ynoic acid
now we have some question about third
the thrid produre:
prepare a solution of 20g sodium hydroxide in 500 ml water
and stire magnetically in an ice bath untile the tempreture
reach 0-5 degree ,add portionwise 34g of 44-dibromo-3-
methylpyrazoble-5-one .stir reaction mixture for 1 hour and
at room for 1 hour .acidified it with hydrochlroci acid . extract
reaction with ether ,and remove solvent and we will get
orange oil and allow to stand untile solidified ,
now we have two question :
first , which solvet can replace ether to extract , ether is
dangours in this season :
second : when we get oraner oil , which solvent we can add
in , and how to refine ,
thanks
look forward to reply .
[Edited on 24-7-2011 by romanceliu]
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