Question

Suggestion: Weigh the sucrose directly into a flask. Measule uut liie Wutur using a measuring cylinder. Weigh out the ethyl acetoacetate and add by pipet Reduction using Sodium Borohydride Weigh ethyl acetoacetate (1.5 g) into a round bottomed flask. Add ethanol (15 mL) to dissolve it. Add a magnetic stir bar and fit the flask with a drying tube. Cool the flask in a bath of ice water. Add sodium borohydride (0.5 eg) portionwise (beware of effervescence!). Stir at room temperature for 1 hour Quench the excess hydride by cautious addition of saturated ammonium chloride solution. Using a rotary evaporator, remove most of the ethanol. Add sufficient water to dissolve any solids (these will be precipitated inorganic salts). Extract twice with ether. Wash the combined organic layers with brine. dry them over MgSO4, filter off the drying agent, and then evaporate the ether. Suggestion: Measure out the methanol using a measuring cylinder. Remember to add a magnetic stirrer bar so that you can use the hotplate stirrer to do the stirring for you. A good time for a lunch break would be while the NaBHA reaction is stirring, unless you are using this time to filter the yeast mixture.

What is the amt of ammonium chloride solution, ether for extraction, brine for extraction and MgSO4 needed. Please show calculations!

Answer 1

1) Hear ammonium chloride used for quenching of excess unreacted sodiumborohydrate in the reaction mixture. There is no limit of ammonium chloride use, the quantity depends on untill to reach ph off the reaction mixture. then we confirm the sodiumborohydrate was decomposed.

2) ether is used for extraction of our product, there is no limit mostly it depends on solubility of our product. It is a liquid liquid extraction. Commonly 4 to 6 times of our product.

Example: our product is sold, 1gram it soluble in 6grams ether

3) salt water washing is given to organic layer is to remove Undissolved salts in organic layer. Commenly half quantity to the organic layer.

4) megnisiumsulphate is used for drying off organic layer. Thank you.