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Chemspider links: 4-chlorobenzaldehyde acetonitrile water ethylene glycol 4-chlorobenzaldehyde ethylene glycol hemiacetal 4-chlorobenzaldehyde hydrate

Researcher

Cuepil Choi

Objective

To test whether the 4-chlorobenzaldehyde would form a hemiacetal with the ethylene glycol and whether it would react with water. Acetonitrile was used to solve low solubility issues with 4-chlorobenzaldehyde going into ethylene glycol and water.

Procedure

0.2096 g of 4-chlorobenzaldehyde, 1.0826 g of acetonitrile, and 0.1851 g of ethylene glycol were mixed together in 1-dram non screwcap vial 1-E through retriturating the mixture several times. The solution was pipetted into NMR tube 1 and an HNMR spectrum was taken within 30 minutes of mixing. A second mixture of 0.2065 g of 4-chlorobenzaldehyde, 1.1070 g acetonitrile, and 0.1321 g of deionized water were mixed together in 1-dram non screw cap vial 2-W through retriturating the mixture several times. The solution was pipetted into NMR tube 2 and an HNMR spectrum was taken within 30 minutes of the mixing. Both NMR tubes were coaxial inner insert tubes placed in an outer tube with deuterated water. The HNMR were taken at 26.3 C

Results

Data sheet 1 - ethylene gylcol acetonitrile
Data Sheet 2 - water
HNMR spectrum 1 of 1-E (ethylene glycol, acetonitrile, 4-chlorobenzaldehyde)
HNMR spectrum 2 of 1-W (water, acetonitrile, 4-chlorobenzaldehyde)

Discussion

The lack of reaction with 4-chlorobenzaldehyde and water or ethylene glycol was unexpected and shows that the solvent that we used, acetonitrile, may inhibit the formation of hemiacetals. The solution never reacted and was at equilibrium within 30 minutes.

Conclusion

The 4-chlorobenzaldehyde did not react with the ethylene glycol or the water. No detectable amounts of hemiacetals were formed in both solutions.

Log

2013-07-10

11:22 mass of 1-dram vial popcap (non screwcap) 1-E was 4.6421g
11:28 0.2096g of 4-chlorobenzaldehyde added to 1-E
11:31 1.0826g of acetonitrile added to 1-E
11:33 0.1851g ethylene glycol added to 1-E
11:35 mixed contents 1-E. 4-chlorobenzaldehyde crystals went in easily.
11:35 1-E was pipetted into coaxial insert NMR tube with 60uL capacity.
11:35 Outer NMR tube filled with D2O as reference
11:40 1-E was capped
11:40 second 1-dram vial 2-W weights 4.7040g
11:43 0.2065g 4-chlorobenzaldehyde added to 2-W
11:44 1.1070g of acetonitrile added to 2-W
11:47 0.1321g of deionized water added to 2-W
11:48 2-W retriturated
11:50 2-W pipetted into coaxial insert NMR tube with 60uL capacity
11:59 HNMR spectrum 1 taken of 1-E at 26.3 C
12:00 deuterated water peak on the HNMR spectrum 1 was corrected to 4.8ppm
12:15 HNMR spectrum 2 taken of 2-W at 26.3 C
12:15 deuterated water peak on the HNMR spectrum 2 was also corrected to 4.8ppm