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