CRSEXP015

=Researcher= Cuepil Choi =Objective= To observe what happens when ethylene glycol and 4-chlorobenzaldehyde is refluxed at a mole ratio close to 1:1. CRSEXP006 showed that 4-chlorobenzaldehyde in excess ethylene glycol produces acetals. A mole ratio closer to 1:1 may yield different products. =Procedure= Ethylene glycol and 4-chlorobenzaldehyde were mixed together in a mole ratio of 1:1.5 in a test tube capped lightly. Mixture was placed in a glycerol bath and was refluxed for approximately 3 hrs. =Results= [|HNMR spectrum 1] - after a 3 hr reflux (there is a .22 shift to the right in the whole spectrum) =Discussion= Although we do not know what compounds this experiment exactly produced, it does seem that several side products were produced during the 1:1.5 mole ratio reflux. THe small amount of unreacted ethylene glycol and 4-chlorobenzaldehyde can be attributed to the molecules having trouble finding each other within the solution. =Conclusion= The large majority of the product seems to be the acetal. However, not all of the 4-chlorobenzaldehyde was converted and there seems some different aromatic compounds that were created. One of the different aromatic compounds may be the acetal of 4-chlorobenzaldehyde and ethylene glycol that isn't cyclized. Pliev70 (picture below) suggests that the multiplet patter around 3.5-3.7 ppm may be the uncyclized form. The aldehyde to acetal ratio is approximately 1:9 from a manual integration. =Log=

2013-08-09
15:04 weight of beaker and test tube 1 was 65.073 g 15:12 0.438 g of 4-chlorobenzaldehyde added to test tube 1 15:18 0.293 g of ethylene glycol added to test tube 1 15:22 glycerol added to an outer beaker and test tube placed inside glycerol bath cap place loosely on top of test tube 1 15:23 hot plate set to 300 C *note: glycerol turned yellow after heating 15:45 reached reflux 18:20 hot plate turned off

2013-08-09
10:02 HNMR 1 taken with D2O