STEP 1: Place a mixture of 114 g (140 ml, 1.0 mol) of heptan-2-one (1), 300 ml of rectified spirit (95% ethanol) and 100 ml of water in a 1.5-litre three-necked flask fitted with an efficient double surface condenser and a thermometer dipping into the reaction mixture.
STEP 2: Through the third neck add 65 g (2.8 mol) of clean sodium, preferably in the form of wire although small pieces may be used with somewhat inferior results, gradually and at such a rate that the reaction is under control; cool the flask in running water or in ice during the addition.
STEP 3: The temperature should not rise above 30 °C. When the sodium has completely reacted, add 1 litre of water and cool the mixture to about 15 °C.
STEP 4: Separate the upper layer, wash it with 25 ml of dilute hydrochloric acid (1:1), then with 25 ml of water, and dry with anhydrous potassium carbonate or anhydrous calcium sulphate.
STEP 5: Distil through an efficient fractionating column and collect the heptan-2-ol at 156-158 °C. The yield is 75 g (65%).
Notes to keep in mind:
1. The ketone may be synthesised; it is also available commercially. The latter should first be dried, redistilled, and the fraction, b.p. 150-152 °C, collected.Cognate preparations. Hexan-2-ol.
- Dissolve 100 g (123 ml, 1 mol) of hexan-2- one in 750 ml of ether, add 150 ml of water and stir the mixture vigorously.
- Introduce 69 g (3 mol) of clean sodium in the form of wire (or small pieces) as rapidly as possible; the reaction must be kept under control and, if necessary, the flask must be cooled in ice or in running water.
- When all the sodium has reacted, separate the ethereal layer, wash it with 25 ml of dilute hydrochloric acid (1:1), then with water, dry with anhydrous potassium carbonate or with anhydrous calcium sulphate and distil through a fractionating column.
- Collect the fraction of b.p. 136-138 °C. The yield of hexan-2-ol is 97 g (95%).
Cyclopentanol. Use cyclopentanone and proceed as for hexan-2-ol. Collect the cyclopentanol as a fraction of b.p. 139-142 °C.
No comments:
Post a Comment
We specialize in producing high value chemicals. Besides our regular products, we strive to develop new products based on customer’s requirements. Our R&D center plays crucial role in handling complex chemistries and developing newer technologies. We respect intellectual property rights and have confidentiality agreement with various multi national companies. We undertake contract manufacturing of fine chemicals and advance intermediates of API’s.