Organic 2 Review Problem 184

Organic 2 Review Problem 184 - i68 P RACTICAL ORGANIC...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
i68 PRACTICAL ORGANIC CHEMISTRY Yield of crude product, 14 g., the high value being due to traces of polynitro-derivatives. Recrystallise the crude pale yellow product from methylated spirit, filter at the pump, wash quickly with a few ml. of fresh spirit, and then drain and dry. The yeJlow o -nitroacetanilide remains in the filtrate, whilst the p -nitroacetanilide is obtained as colourless crystals, m.p. 214°. A second recrystallisation of the para compound should not be necessary. Yield of pure product, 8 g. Hydrolysis to p-Nitroaniline. For this purpose use 70% sulphuric acid, the usual reagent employed for the hydrolysis of anilides (p. 108). Add 5 g. of the recrystallised p -nitro- acetanilide to 30 ml. of 70% sulphuric acid, and boil the mixture gently under a reflux water-condenser for 20 minutes. Then pour the clear hot solution into about 150 ml. of cold water, and finally add an excess of sodium hydroxide solution until precipi- tation of the yellow p -nitroaniline is complete. Cool the mixture
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.
Ask a homework question - tutors are online