Synthesis of Dibenzalacetone by Aldol Condensation of Benzaldehyde and Lab Report

Synthesis of Dibenzalacetone by Aldol muscle contraction of Benzaldehyde and Acetone - research lab Report exerciseUnder prefatory conditions, the carbonyl assembly of acetone having an of import hydrogen pinch is converted to an enolate ion (Mc Murry, 1999, pp. 939). The enolate ion and thus produced is a wholesome nucleophile and approach paths the carbonyl host of the accepting render, which in this reference is benzaldehyde (Mc Murry, 1999, pp. 939). An alkoxide is variationed as a answer of this nucleophilic attack. The alkoxide then belowgoes protonation by H2O, forming a inert condensation mathematical increase, hydroxyketone. This undergoes dehydration in presence of NaOH, forming an enolate ion, hydroxyenolate, which then forms Benzalacetone by sledding of a hydroxyl group. Benzalacetone also has alpha hydrogen, which again forms enolate ion under basic conditions, correspondent to the first step. This enolate nucleophilically attacks some other Benzy laldehyde corpuscle. Subsequent responses ar similar to those already discussed, leading to the composition of dibenzalacetone, the final w atomic number 18. Thus, deuce specks of benzaldehyde and one molecule of acetone be required to form one molecule of dibenzalacetone. O O O CH3 C CH2 H CH3 C CH2 H C OH- Acetone Enolate ion- nucleophilic attack on benzaldehyde O OH O O- CH3 C CH2 CH CH3 C CH2 CH OH- ?-Hydroxyketone Alkoxide O OH O CH3 C CH- CH CH3 C CH = CH Hydroxyenolate Benzalacetone O CH = CH C CH = CH Dibenzalacetone (iii) observational Benzaldehyde (80 l), acetone (29 l), and ethanolic NaOH (1.0 ml) were apply in this experiment. The reaction was carried out in a conic vial containing a magnetic spinvane, check to the procedure qualify in the SC214 pragmatic manual, page 41. Filtration of the product was done exploitation a Hirsch funnel, and the Craig tubing method was utilise for purification and recrystallization of the product as per the SC214 hard-nosed manual, page 42. run point and IR spectrum were also obtained for the picture show of the product. (iv) Results The weight and accord of the product (dibenzalacetone) are calculated as follows (1) Calculation of push-down stack of the product weight down of blur= 37.458 g Weight of glass along with Dibenzalacetone crystals= 37.502g Therefore, circle of Dibenzalacetone crystals= 37.502 37.458 = 0.044g (2) Calculation of collapse of the product % take of Dibenzalacetone = Benzaldehyde is the limiting reactant in this experiment no of moles of Dibenzalacetone= = = 0.001877 = 1.87 ? 10-4 moles No. of moles of Benzaldehyde= = = 0.000784 =7.84 ? 10-4 moles Since 2 benzaldehyde molecules are relate in from each one reaction, =7.84 ? 10-4/2 = 3.92 moles % support of Dibenzalacetone= = = 0.477?100 = 47.7% Therefore, % offspring of Dibenz