View attachment 65496
Place 25 grams of dry acetamide in a 350ml conical or flat-bottomed flask, and add 69 grams (23ml) of bromine (CAUTION!): a deep red liquid is produced. Cool the flask in ice water and add 10 per cent.
sodium hydroxide solution (about 210ml) in small portions and with vigorous shaking or stirring until the solution acquires a pale yellow color. At this stage the bromoacetamide is present in the alkaline solution.
If any solid should crystallize out, add a little water. Using a 1-liter distilling flask; replace the filter flask receiver by a small funnel attached to the end of the condenser by a short length of rubber tubing and dipping about 0.6 cm below 100ml of dilute hydrochloric acid (1:1) contained in a beaker. Place a solution of 60 grams of sodium hydroxide in 150ml of water, together with a few fragments of porous porcelain, in the
flask and the bromoacetamide solution in the separatory funnel.
Warm the solution in the flask until the thermometer in the liquid reads 60-70°C. Allow the bromoacetamide solution to run slowly into the flask at such a rate that the temperature does not rise above about 70°C; heat is evolved in the reaction and if the temperature rises above 75°C the flask should be surrounded momentarily by a bath of cold water.
When all the solution has been added, maintain the temperature of the mixture in the flask for about 15 minutes at 65-70°C; by this time the solution should be clear and colorless. Gently boil the solution and thus drive off the methylamine vapor into the dilute hydrochloric acid. As soon as the distillate is no longer alkaline (40-60minutes), concentrate the hydrochloric acid solution by placing it in a 250ml distilling flask connected with a water condenser and distilling carefully from an air bath until about 25ml remains; then transfer the solution to an evaporating-dish evaporate to dryness on a water bath, and finally for a short time in an air oven at 100-105°C.
The yield of crude dry product (which is contaminated with some ammonium chloride) is about 24 grams. Transfer the finely-powdered, dry solid to a 250ml round-bottomed flask fitted with a reflux condenser and cotton wool (or calcium chloride) guard tube.
Add about 120ml of ABS ethyl alcohol (which dissolves only the methylamine hydrochloride) and boil the mixture for 10 minutes Filter though a hot water funnel.
Extract the residue with a further 50ml of boiling ABS ethyl alcohol and filter again.
Cool the combined alcoholic extracts when colorless crystals of methylamine hydrochloride will separate out.
Filter rapidly at the pump, and transfer the crystals (which are deliquescent) to a stoppered bottle.
Evaporate the filtrate to about one third of the original volume, when a further crop of crystals will be obtained. Dry all the crystals in a
desiccator.
The yield is about 18 grams.
Place 25 grams of dry acetamide in a 350ml conical or flat-bottomed flask, and add 69 grams (23ml) of bromine (CAUTION!): a deep red liquid is produced. Cool the flask in ice water and add 10 per cent.
sodium hydroxide solution (about 210ml) in small portions and with vigorous shaking or stirring until the solution acquires a pale yellow color. At this stage the bromoacetamide is present in the alkaline solution.
If any solid should crystallize out, add a little water. Using a 1-liter distilling flask; replace the filter flask receiver by a small funnel attached to the end of the condenser by a short length of rubber tubing and dipping about 0.6 cm below 100ml of dilute hydrochloric acid (1:1) contained in a beaker. Place a solution of 60 grams of sodium hydroxide in 150ml of water, together with a few fragments of porous porcelain, in the
flask and the bromoacetamide solution in the separatory funnel.
Warm the solution in the flask until the thermometer in the liquid reads 60-70°C. Allow the bromoacetamide solution to run slowly into the flask at such a rate that the temperature does not rise above about 70°C; heat is evolved in the reaction and if the temperature rises above 75°C the flask should be surrounded momentarily by a bath of cold water.
When all the solution has been added, maintain the temperature of the mixture in the flask for about 15 minutes at 65-70°C; by this time the solution should be clear and colorless. Gently boil the solution and thus drive off the methylamine vapor into the dilute hydrochloric acid. As soon as the distillate is no longer alkaline (40-60minutes), concentrate the hydrochloric acid solution by placing it in a 250ml distilling flask connected with a water condenser and distilling carefully from an air bath until about 25ml remains; then transfer the solution to an evaporating-dish evaporate to dryness on a water bath, and finally for a short time in an air oven at 100-105°C.
The yield of crude dry product (which is contaminated with some ammonium chloride) is about 24 grams. Transfer the finely-powdered, dry solid to a 250ml round-bottomed flask fitted with a reflux condenser and cotton wool (or calcium chloride) guard tube.
Add about 120ml of ABS ethyl alcohol (which dissolves only the methylamine hydrochloride) and boil the mixture for 10 minutes Filter though a hot water funnel.
Extract the residue with a further 50ml of boiling ABS ethyl alcohol and filter again.
Cool the combined alcoholic extracts when colorless crystals of methylamine hydrochloride will separate out.
Filter rapidly at the pump, and transfer the crystals (which are deliquescent) to a stoppered bottle.
Evaporate the filtrate to about one third of the original volume, when a further crop of crystals will be obtained. Dry all the crystals in a
desiccator.
The yield is about 18 grams.
