Experiments on the preparation of 1-bromobutane
Experiments on the preparation of 1-bromobutane
This experiment is from the official website of Tianjin Agricultural College
Operation method
Experiments on the preparation of 1-bromobutane
Materials and Instruments
Semi-micro Organic Preparation Instrument Round-bottomed Flask Spherical Condenser Tube Pipes Pipes Small Glass Funnel Measuring Cylinder 250 mL Beaker 75° Bend Tube Straight Condenser Tube Tube Tailpipe Vacuum Plug Tubular Dividing Funnel Round-bottomed Flask 30 mL Cone Flask Steamer Heads Thermometer Sleeves Thermometers Move Drugs: 4 mL concentrated H2SO4, 2.5 mL n-C4H9OH; 3.3 g NaBr; saturated NaHCO3 solution Caveat 1. Add concentrated sulfuric acid in small quantities, add and cool, and add sodium bromide after thorough cooling. 2. When reflux should be small fire, pay attention to the hydrogen bromide absorption device, the glass funnel should not be immersed in water to prevent backsiphonage. 3. Pay attention to the order of washing, which layer is the product to be clear, liquid separation should be thorough. 4. The final distillation apparatus should be dry, the desiccant shall not be poured into the distillation flask. For more product details, please visit Aladdin Scientific website.
Apparatus: semi-micro-organic preparation apparatus
25 mL round-bottomed flasks; spherical condenser tubes; air guide tubes; small glass funnels; 10 mL measuring cylinders; 250 mL beakers; 75-degree bends; straight condenser tubes; pick-up tubes; vacuum plugs; two cylindrical dispensing funnels; 5 mL 2 round-bottomed flasks; 1 30 mL conical flask; distillation head; thermometer casing; thermometer (200 °C);
Heating jacket 250 mL.
In a 30 mL garden-bottomed flask, add 3.3 mL of water and 4.0 mL of concentrated sulfuric acid, mix well, and cool to room temperature. Add 2.5 mL of n-butanol and 3.33 g of sodium bromide, shake, add a few grains of zeolite, attach a reflux condenser tube, connect a hydrogen bromide absorber to the upper end of the condenser tube (so that the mouth of the funnel just touches the water surface, do not immerse in the water, so as not to be sucked back up), and use a 5% solution of sodium hydroxide as the absorbent.
The flask was heated on an asbestos mesh and refluxed for 0.5 h. During refluxing, the flask was shaken continuously to make full contact with the reactants. After the reaction was completed, the flask was slightly cooled and converted into a distillation unit to vaporize the crude n-bromobutane until the distillate was clear.
With a capillary buret, the distillate was transferred to a separatory funnel, washed with 3.3 mL of water, and the aqueous layer was separated. The organic phase was transferred to another dry separatory funnel and washed with 1.7 mL of concentrated sulfuric acid once, and the sulfuric acid layer was separated. The organic layer was washed once with water, saturated sodium bicarbonate solution and water 3.3 mL each in turn to be neutral, and then the n-bromobutane organic layer was separated out and dried in a conical flask, dried with anhydrous calcium chloride and distilled to collect the fraction at 99~103°C. The organic layer was then washed once with water, saturated sodium bicarbonate solution and water. Weigh and calculate the yield.