Synthesis & Distillation of Isopentyl Acetate using Acetic Acid and Isopentyl alcohol

Synthesis & Distillation of Isopentyl Acetate using Acetic Acid and Isopentyl alcohol

TA: Pallav Kumar  TH 2:!":

Abstract:

Isopentyl Acetate #$anana oil% as synthesi'ed (y com(ining a car(o)ylic acid ith an alcohol forming an ester #isopentyl alcohol%* In +I,* - the reaction shoed acetic acid and isopentyl alcohol (eing com(ined to form isopentyl acetate* +or the reaction to  proceed a reflu) techni.ue as used* After the synthesis as performed a distillation  procedure as performed to purify the isopentyl acetate* The (oiling point for the  purified isopentyl acetate as appro)imately -"/*01* There ere still a fe impurities for the purified sample as the (oiling point shoed3 and the calculated percentage yield as 045*

+I,*-* 6eaction of acetic acid and isopentyl alcohol reacting to form isopentyl acetate*

Introduction:

Isopentyl acetate is a colorless li.uid that is only slightly solu(le in ater3 (ut very solu(le in most organic solvents* Isopentyl acetate has a strong odor7 it smells very much li8e a (anana* It is used as a solvent for some varnishes and nitrocellulose lac.uers3 as ell as (eing a honey(ee pheromone and can (e used to attract large groups of honey(ees to a small area* The intense smell3 pleasant odor and lo to)icity of isopent yl acetate help to test the effectiveness of respirators or gas mas8s.In the e)periment isopentyl alcohol as treated ith acetic acid to synthesi'e acetaminophen3 and as induced (y using a reflu)* A distillation method as then applied to purify the isopentyl acetate*

+I,*2* The overall reaction shows an addition reaction, where the acetic acid

becomes deprotonated and a ester group exchanges places with it.

+ig*"* The image a(ove shos the mechanism

+igure "* shos in detail ho the mechanism as performed3 hat happened in the first step as the car(o)ylic acid accep ted a proton from the strong acid catalyst3 then the non!(onded electrons of the alcohol attac8ed the positively charged car(onyl car(on to give a intermediate* A proton as lost at the o)ygen and gained at ano ther* The mechanism then lost a ater molecule giving a protonated ester* The last step in the mechanism as the transfer of a proton from the second hydro)yl group3 hich forms the ester #the product%* Determining the (oiling point and percent recovery ould determine the success of the e)periment* The (oiling point of the final compound as determined and compared to the literature (oiling point3 hich as -4

* If the (oiling point of

°

the purified isopentyl acetate ere more9less than 0 degrees from the literature (oiling  point then it ould have not (een accurate and could not support the identity of isopentyl alcohol* Percent recovery as measured (y the ta8ing actual amount of grams of isopentyl acetate o(tained divided (y the theoretical num(er of grams that should have  (een produced* The goal of the la( as to synthesi'e isopentyl acetate correctly and perform the  procedures in order to get a pure sample of the ester and a great percent recovery* A  possi(le pro(lem that could have occurred ould have (een that there could have (een impurities still left in the final product3 or the temperature not (eing constant could have  played a factor hen doing the reflu) and distillation*

Procedure:

To (egin the e)periment3 an empty 0!ml conical vial as eighed and -* ml of isopentyl alcohol as added3 a reflu) as assem(led #a drying tu(e contained calcium chloride as attached to reflu)%* The conical vial containing the alcohol as then reeighed to o(tain an accurate eight* Then -*0 m of glacial acetic acid as a dded37 three drops of concentrated sulfuric acid ere added carefully to the vial* A small magnetic spin vane as added to the vial and heated* The vial containing the compounds here then reflu)ed for ; minutes at -sing a pipet -* m of sodium  (icar(onate as used to separate organic and a.ueous layers #done " times total%* The  (ottom a.ueous layer as then removed and disposed* The organic layer #isopentyl acetate% as then dried ith sodium sulfate* The ne)t method used as distillation3 using a still head and a ater!cooled condenser3 hich as used to purify the isopentyl acetate* The final product as then eighed and percent yield and (oiling point ta8en3 and to infrared spectrum graphs ere o(tained*

Results and Calculations:

Ta(le -* omparison of literature (*p* and eight of initial and final product $oiling Point #=% -4=

iterature Initial +inal

?eight #g% -* *