exp269

UC-EXP269scheme.png

Researcher

Evan Curtin

Objective

To synthesize three imines from salicylaldehyde(1) , 4-(dimethylamino)benzaldehyde(2) and 4-anisaldehyde(3) with aniline to investigate solubility data.

Procedure

1) Salicylaldehyde (6.1018g, 50mmol) was dissolved in ethanol (12.181g, 15.433mL) in an Erlenmeyer flask. Aniline (4.6529g, 50mmol) was added slowly to the solution. Stirred at RT for 21 hours. Cooled over ice, filtered. The solid product was dried in a desiccator under high vacuum. The product was characterized by melting point and HNMR.

2) 4-dimethylaminobenzaldehyde (7.4542g, 50mmol) was dissolved in ethanol (69.819g, 88.457mL) in an Erlenmeyer flask. Aniline (4.6529g, 50mmol) was added slowly to the solution. Stirred at RT for 21 hours. Cooled over ice, filtered. The solid product was dried in a desiccator under high vacuum. The product was characterized by melting point and HNMR.

3) Salicylaldehyde (6.8026g, 50mmol) was dissolved in ethanol (11.173g, 14.156mL) in an Erlenmeyer flask. Aniline (4.6529g, 50mmol) was added slowly to the solution. Stirred at RT for 94 hours. Cooled over ice, filtered. The solid product was dried in a desiccator under high vacuum. The product was characterized by melting point and HNMR.

Results

EXP269plan sheet

Characterization of 1C:
appearance: yellow solid
amount: 6.5600g, 67% yield
mp: 47-48°C
HNMR:



Characterization of 2A:
appearance: bright yellow solid.
amount: 2.3191, 21% yield.
mp: 95-97°C
HNMR: Solvent is CDCl3


Characterization of 3B:

appearance: yellow solid
amount: 9.7022g, 92% yield.
mp: 60-62°C
HNMR: Solvent is CDCl3


Discussion

1) The melting point for salicylideneaniline was determined to be 47-48C, slightly lower than the previous value of 49.5C.
2) The melting point of N-(4-Dimethylaminobenzylidene)aniline was 96C, which is slightly lower than previous values for the compound.
3) The melting point for N-(4-methoxybenzylidene)aniline was found to be 60-62°C, slightly lower than previously determined melting points of 62.3C and 65C

[quantify any impurities if present JCB]

Conclusion

salicylideneaniline, N-(4-Dimethylaminobenzylidene)aniline, and N-(4-methoxybenzylidene)aniline were all successfully synthesized in ethanol. The first and third compound were made at 2M concentration, while N-(4-methoxybenzylidene)aniline had to be diluted due to lower solubility of starting materials.

Log

2011-06-23

13:18 - Measured 50mmol of each reactant. Mixed each aldehyde with ethanol to form a solution in an Erlenmeyer flask. The amount of ethanol used was enough to run each reaction at 2M (12.181g (1) 10.619g (2) and 11.173g (3))
13:30 - 4-(dimethylamino)benzaldehyde (2) won't dissolve completely, diluted to 1M with 19.733g ethanol.
13:33 - (2) still has solid reactant, diluted once more to 0.5M with 39.467g ethanol. . The reactant dissolved completely
13:44 - Added 50mmol aniline to each aldehyde solution, set to stir on stirring plate.
13:53 - No noticeable change in any solution.
14:35 - No noticeable change in any solution
15:10 - The solution that started with 4-anisaldehyde (3) formed solid precipitate. There is not enough liquid to extract the solid from the Erlenmeyer flask. Added a few mL ethanol to dissolve the product, then transferred to a beaker.
15:48 - Cooled solution down with an ice/water bath. Precipitate formed. Filtered using Buchner funnel and house vacuum.
16:10 - Put sample (3) in desiccator under high vacuum. Mass of the vial and cap containing the solid is 13.9283g. Total mass before putting the sample into the desiccator is 26.1821g.

2011-06-24

10:56 - Observed solutions 1 and 2. 1 Formed precipitate, 2 did not.
11:03 - Chilled 1 in an ice/water bath.
11:04 - Removed 3 from desiccator. Sample is now 3A. It is a light yellow solid.
11:16 - Filtered 1 with Buchner funnel using house vacuum.
11:20 - Put solid from 1 in desiccator under high vacuum.
11:36 - Took some of sample 3A and dissolved in CDCl3, put in NMR tube.
12:53 - Took HNMR of 3A using 300MHz varian NMR.
12:58 - Put 3A into desiccator under high vacuum.

2011-06-27

11:58 - Observed sample 2, precipitate formed.
12:03 - Chilled sample 2 in an ice/water bath.
12:08 - Removed samples 1 and 3 from desiccator. Both are light yellow solids.
12:11 - Filtered sample 2.
12:15 - Weighed 1 and 3. 1 is 6.7406g and 3 is 9.7022g.
12:34 - Put sample 2 in desiccator under high vacuum.
14:12 - Removed sample 2 from desiccator, it is a bright yellow solid.
14:46 - Added CDCl3 to samples 1A, 2A, 3B and all of the starting materials. Added to NMR tubes.
16:14 - Took HNMR of 1A, 2A, 3B, salicylaldehyde, p-dimethylaminobenzaldehyde, p-anisaldehyde, and aniline using a 300MHz varian NMR

2011-06-29

11:08 - Weighed 2A, mass is 2.3191g.
11:22 - Took melting point of 1A, 2A and 3B. The melting point for 1A is 46.5-48.5C, for 2A is 95-97C, and for 3B is 60-62C.
11:54 - Put 1A in desiccator under high vacuum.

2011-07-01

10:20 - Removed 1A from desiccator, sample is now named 1B.
10:30 - Took some of sample 1B, added CDCl3, and put in NMR tube.
10:45 - Took HNMR of 1B using 300MHz varian NMR. The spectrum has a peak

2011-07-5

12:15 - Prepared sample with CDCl3, put in NMR tube.
12:42 - Took HNMR of 1B (second scan) using 300 MHz varian NMR.
12:47 - Split sample into two vials, put both into a desiccator under high vacuum.