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Calculation of percentage yield of nitrone

Materials and Methods

Protocol was titled Synthesis and application of a radical trapping agent was obtained from CHEM 3880-A1. For the synthesis of N-Benzylidene-tert-butylamine N-Oxide (2) in a 50 mL Erlenmeyer flask along with a flea sized stir bar 0.91 mL of N-tert-buyl benzylamine , 0.07 g of Na2 WO42H2O and 10 mL of methanol was placed. The solution was cooled in an ice bath and 1.5 mL of 30% aqueous hydrogen peroxide was added. The mixture was removed from the ice bath and was left to stir for one hour on a stir plate. Upon completion of an hour, the flask was stoppered and it was placed in our draw until the next lab period 10/24/13. At the next lab period the mixture was poured into a 25 mL round bottom flask and placed on the rotary evaporator to dry. Once dried 25 mL of methylene chloride was added to it and then was poured into a separatory funnel. It was then washed twice with 10 mL portions of saturated aqueous sodium chloride. Then the mixture was separated and the bottom layer was collected in a 25 mL Erlenmeyer flask. Then the methylene chloride solution was dried over anhydrous sodium sulfate. The drying agent was removed by filtration and the methylene chloride was evaporated on a hot plate. The residue crystallized upon cooling and using a glass rod to scratch the bottom of the flask. The product was recrystallized for a small amount of hexane. The product was collected by filtration and the dry product was weighed to be 0.6010 g. Melting point was taken and found to be 72.5-75.0 and H NMR was taken in Chloroform. Once our nitrone 2 was made we placed 10 mg of nitrone and 15mg of benzoyl peroxide in a vial and added 1 mL of benzene and then carefully sparged the solution with nitrogen for 3 minutes. Then about 0.5 mL of the solution was transferred to a serum-capped, nitrogen flushed ESR sample tube. The tube was heated in a 45 degree Celsius water bath for 5 minutes then the ESR spectrum was immediately taken.
Results
An 1H-NMR spectrum of the compound was run in deuterated chloroform (CDCl3). An ESR spectrum of the compound was run. The 1H-NMR and ESR spectrum peaks are tabulated in table I. The 1H-NMR and ESR spectrum integrated values are tabulated in table II. The melting point was determined to be 72.5 - 75.0oC.
Table I. Peaks of 1H-NMR in chloroform and ESR
1H-NMR (ppm) ESR
8.25, 7.60, 7.40, 7.25, 5.25, 3.90, 3.75, 3.50, 1.60, 1.50, 1.25, 1.00

Table II. Integration values of 1H-NMR in chloroform and ESR.
1H-NMR ESR
1.00, 0.43, 1.46, 0.61, 9.16, 4.53, 5.56, 7.43, 14.56, 4.69

Peak assignments: 1.60 (9H, tBu-H), 7.25 (m, 3H, Ph-H), 7.60 (1H, C-H), 8. 25 (2H, Ph-H). These compare well with the literature values of 1.62, 7.35, 7.55, and 8.29 (Give the Andrade reference here). The other peaks are from solvent and perhaps unreacted reactants - 7.25 (CDCl3), 1.00 (TMS). If you want to assign the other non-product peaks, look at the NMR of the reactants and see if they match up. The melting point from literature is 72oC and use the Andrade reference here as well.

Have #1 and #4 listed below been answered in the information you provided

1. Calculation of percent yield of nitrone 10 _____
2. m. p. of nitrone (compare with literature value; incl. reference) 10 _____

H NMR spectrum* of nitrone
3. quality of spectrum 10 _____
4. assignment of resonances 10 _____
5. comparison with literature spectrum (incl. reference) 5 _____

ESR spectra*
6. quality of spectrum 10 _____
7. interpretation of spectrum
8. determination of hyperfine coupling constant values 10 _____
9. calculation of g value 10 _____
10. comparison of spectral parameters with literature data (incl. reference) 5 _____

Formatting and appearance of report 10 _____

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Materials and Methods

Protocol was titled Synthesis and application of a radical trapping agent was obtained from CHEM 3880-A1. For the synthesis of N-Benzylidene-tert-butylamine N-Oxide (2) in a 50 mL Erlenmeyer flask along with a flea sized stir bar 0.91 mL of N-tert-buyl benzylamine , 0.07 g of Na2 WO42H2O and 10 mL of methanol was placed. The solution was cooled in an ice bath and 1.5 mL of 30% aqueous hydrogen peroxide was added. The mixture was removed from the ice bath and was left to stir for one hour on a stir plate. Upon completion of an hour, the flask was stoppered and it was placed in our draw until the next lab period 10/24/13. At the next lab period the mixture was poured into a 25 mL round bottom flask and placed on the rotary evaporator to dry. Once dried 25 mL of methylene chloride was added to it and then was poured into a separatory funnel. It was then washed twice with 10 mL portions of saturated aqueous sodium chloride. Then the mixture was separated and the bottom ...

Solution Summary

The percentages of yield of nitrone are given.

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