Synthesis of T-Pentyl Chloride
Exp 23 B
Synthesis of t-Pentyl Chloride
11-8-12
Purpose: The sysnthesis of t-Pentyl Chloride from alcohol.
Procedure:
Preparation of t-Pentyl Chloride. In a 125-mL separatory funnel, place 10.0 mL of t-pentyl alcohol (2-methyl-2-butanol, MW _ 88.2, d _ 0.805 g/mL) and 25 mL of concentrated hydrochloric acid (d _ 1.18 g/mL). Do not stopper the funnel. Gently swirl the mixture in the separatory funnel for about 1 minute. After this period of swirling, stopper the separatory funnel and carefully invert it. Without shaking the separatory funnel, immediately open the stopcock to release the pressure. Close the stopcock, shake the funnel several times, and again release the pressure through the stopcock (see Technique 12, Section 12.4). Shake the funnel for 2_3 minutes, with occasional venting. Allow the mixture to stand in the separatory funnel until the two layers have completely separated. The t-pentyl chloride
(d _ 0.865 g/mL) should be the top layer, but be sure to verify this by adding a few dropsof water. The water should dissolve in the lower (aqueous) layer. Drain and discard the lower layer.
Extraction. The operations in this paragraph should be done as rapidly as possiblebecause the t-pentyl chloride is unstable in water and sodium bicarbonate solution. It is easily hydrolyzed back to the alcohol. In each of the following steps, the organic layer should be on top; however, you should add a few drops of water to make sure. Wash (swirl and shake) the organic layer with 10 mL of water. Separate the layers and discard the aqueous phase after making certain that the proper layer has been saved. Add a 10-mL portion of 5% aqueous sodium bicarbonate to the separatory funnel. Gently swirl the funnel (unstoppered) until the contents are thoroughly mixed. Stopper the funnel and carefully invert it. Release the excess pressure through the stopcock. Gently shake the separatory funnel, with frequent release of pressure. Following this, vigorously shake the
Synthesis of t-Pentyl Chloride
11-8-12
Purpose: The sysnthesis of t-Pentyl Chloride from alcohol.
Procedure:
Preparation of t-Pentyl Chloride. In a 125-mL separatory funnel, place 10.0 mL of t-pentyl alcohol (2-methyl-2-butanol, MW _ 88.2, d _ 0.805 g/mL) and 25 mL of concentrated hydrochloric acid (d _ 1.18 g/mL). Do not stopper the funnel. Gently swirl the mixture in the separatory funnel for about 1 minute. After this period of swirling, stopper the separatory funnel and carefully invert it. Without shaking the separatory funnel, immediately open the stopcock to release the pressure. Close the stopcock, shake the funnel several times, and again release the pressure through the stopcock (see Technique 12, Section 12.4). Shake the funnel for 2_3 minutes, with occasional venting. Allow the mixture to stand in the separatory funnel until the two layers have completely separated. The t-pentyl chloride
(d _ 0.865 g/mL) should be the top layer, but be sure to verify this by adding a few dropsof water. The water should dissolve in the lower (aqueous) layer. Drain and discard the lower layer.
Extraction. The operations in this paragraph should be done as rapidly as possiblebecause the t-pentyl chloride is unstable in water and sodium bicarbonate solution. It is easily hydrolyzed back to the alcohol. In each of the following steps, the organic layer should be on top; however, you should add a few drops of water to make sure. Wash (swirl and shake) the organic layer with 10 mL of water. Separate the layers and discard the aqueous phase after making certain that the proper layer has been saved. Add a 10-mL portion of 5% aqueous sodium bicarbonate to the separatory funnel. Gently swirl the funnel (unstoppered) until the contents are thoroughly mixed. Stopper the funnel and carefully invert it. Release the excess pressure through the stopcock. Gently shake the separatory funnel, with frequent release of pressure. Following this, vigorously shake the
References: http://answers.yahoo.com/question/index?qid=20080911092315AAXRbXU http://answers.yahoo.com/question/index?qid=20090603175731AAvMEzf A Small Scale approach to organic laboratory techniques, 3rd edition. Pavia, Lampman