Pentamethylene dicyanide

Pimelic acid. Heat a mixture of 18 g. of pentamethylene dicyanide and 250 g. of 50 per cent, sulphuric acid by weight in a 750 ml. round-bottomed flask under reflux for 9 hours. INIost of the pimehc acid separates from the cold reaction mixture. Filter oflF the crystaUine acid upon a sintered glass funnel. Saturate the filtrate with ammonium sulphate and extract it with three 50 ml. portions of ether. Dissolve the residue on the filter (which is shghtly discoloured, but is fairly pure pimehc acid) in the combined ethereal extracts, dry with anhydrous sodium or magnesium sulphate, and remove the ether by distiUation. Recrystallise the residual sohd acid from benzene containing 5 per cent, of ether. The yield of pure pimehc acid, m.p, 105-106°, is 22 g. 

Pentamethylene dibromide, see 1 5-Dibromopentane Pentamethylene dicyanide, 493 2-Pentene, 239 4-Pentyn-l-ol, 896, 901 Peracetic acid oxidation, 755, 768, 893 Perbenzoic acid, 807, 808, 894 analysis of, 809 Performic acid, 893, 894 Periodic acid, 1070 reagent, 1070 ... 

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