CHML212 Exp. 22 Solventless Aldol Condensation IN-LAB ASSIGNMENT: (EACH STUDENT will record the following data in his/her laboratory notebook in a well organized manner during lab period. Yellow carbon copies will be submitted for grading along with Post-Lab assignment.) …..max score = 20 pts. 6. Data/Calculations a. b. c. d. e. f. g. h. i. j. k. l. m. Initial mass of 1-indanone and 3,4-dimethoxybenzaldehyde used mass of filter paper and watch glass mass of watch glass + filter + product Final mass of dry product Physical state and color of product Theoretical yield calculation % yield calculation TLC diagram including all cm measurements Atom economy calculation Experimental atom economy calculation “Eproduct” calculation Cost per synthesis and cost per gram calculations (cost of reagents given in PowerPoint) Experimental melting point 7. In-lab Question (The following questions should be answered in laboratory notebook.) a. Draw the product, and a complete mechanism for its formation, of the reaction shown below. CH3CH2 b. O C + H H3C O C CH3 OH ? Give two specific examples of how this experiment is “greener” than a traditional aldol condensation. What is it about these changes that make the experiment “green”? CHML212 Exp. 22 Solventless Aldol Condensation POST-LAB ASSIGNMENT: (EACH LAB GROUP will submit one copy of a typewritten, paragraph style report addressing all of the points listed below. Must be written using PAST TENSE, PASSIVE VOICE. ) …..max score = 50 pts. 8. Experimental (Write 1-2 paragraphs including all of the following. Do NOT present a bulleted outline.) What type of reaction did you perform? Describe the actual synthetic procedure. Include names of any reactants used and desired product, as well as name of solvent and catalyst used (if any). Be sure to give actual volumes/masses of compounds used during the synthesis (not just what the lab manual tells you to use). Describe the purification technique used to isolate the desired product, including names and actual volume/mass of any compounds used during purification process. Describe the analytical technique used to evaluate the product, including names and actual volume/mass of any compounds used during sample preparation, and any type of spectral analysis used. 9. Results (Complete tables. Once completed, copy/ paste completed tables into your document.) Table 22.1 Experimental results Theoretical Yield (g) Actual Yield (g) Percent Yield Melting Range (oC) Product Appearance Table 22.2 TLC analysis TLC Rf Values Compound 3 sp CH stretch sp2 CH stretch C=O stretch C-O stretch aromatic C=C stretch (2) aldehyde CH stretch (2) Sample 1-indanone 3,4-dimethoxybenzaldehyde Aldol Product Table 22.3 IR analysis 1-Indanone Functional Group Standard Base Values (cm-1) 2800–3000 3000–3100 1680–1740 1000–1300 1500–1600 2700–2800 Frequency (cm-1) 3,4-dimethoxybenzaldehyde Frequency (cm-1) Aldol Product Frequency (cm-1) Table 22.4 Green chemistry results Atom Economy (%) Experimental Atom Economy (%) “Eproduct” Cost per Synthesis ($) Cost per Gram ($/g) 10. Discussion (Write 1-2 pages addressing all of the following points.) Based on the TLC results, were the reactants completely converted to desired product? Explain this conclusion by giving the identity and any Rf values of all standards and any compounds detected in the sample during TLC analysis. Based on your melting point results, did the product appear to be pure? Explain your conclusion by giving the actual literature melting point of the desired product, as well as your experimental melting point. How can IR spectroscopy be used to differentiate between the reactant aldehyde and the Aldol product in this experiment? Give the identity of one type of absorption, and explain how it could be used to determine whether or not the conversion took place. Include the typical frequency and the actual frequency for this type of bond in your statement. Include a short comment addressing what could be done differently to improve the experimental results if repeated.