Ethanol, absolute, preparation reaction with sulphuric acid

Girard s reagent P , C5H5NCH2C0NHNH2 C1. In a 1-htre threenecked flask, equipped as in the previous preparation, place 200 ml. of absolute ethyl alcohol, 63 g. (64 -5 ml.) of pure anhydrous pyridine and 98 - 5 g. (84 5 ml.) of ethyl chloroacetate. Heat the mixture under reflux for 2-3 hours until the formation of the quaternary salt is complete acidify a small test-portion with dilute sulphuric acid it should dissolve completely and no odour of ethyl chloroacetate should be apparent. Cool the mixture in ice and salt. Replace the thermometer by a dropping funnel, and add a solution of 40 g. of 100 per cent, hydrazine hydrate in 60 ml. of absolute ethanol all at once. A vigorous exothermic reaction soon develops and is accompanied by vigorous effervescence. The pro duct separates almost immediately. When cold, filter with suction, wash... 

Ethyl nitrite may be prepared by dissolving 38 g (0.55 mol) of sodium nitrite in 120 ml of water in a 500-ml flask equipped as above. Dilute 23 g (29 ml, 0.5 mol) of ethanol with an equal volume of water, carefully add 25 g (13.5 ml) of concentrated sulphuric acid and dilute to 120 ml with water. Cool both solutions to —10 °C in an ice-salt bath and add the acid-alcohol mixture to the nitrite solution slowly with constant stirring during about 30 minutes. Transfer the reaction mixture to a cooled separating funnel, run off- the lower aqueous phase, wash the ethyl nitrite layer rapidly with ice-cold 2 per cent sodium hydrogen carbonate solution and dry over anhydrous sodium sulphate. The product may be kept at 0°C as a 50 per cent solution in absolute ethanol if required but should be used as soon as possible. The b.p. of pure ethyl nitrite is 17 °C. 

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