Kayla+Gogarty+Fall+2013

Kayla Gogarty
 * Researcher**

The purpose of the CRS research is to use HNMR to analyze the reactions of simple organic compounds. This analysis provides the opportunity to make chemical discoveries and test the validity of fundamental organic chemistry reactions.
 * Purpose of Research**

//Chemical Rediscovery Survey: Acetone and Propylamine// One experiment that I have conducted is the reaction of acetone and propylamine. This experiment was my major focus during the term.
 * Research**

Abstract A new method has been developed that does not require the use of a catalyst. For this method, the reactants are combined in different ratios in glass vials. The mixtures are then placed in a coaxial insert NMR tube with the deuterated solvent in an outer NMR tube. The reaction of acetone and propylamine forms N-propyl-2-propanimine, which is a ketoimine, when there is a 50/50 by volume mixture of the two reactants, one drop of acetone in excess propylamine, or one drop of propylamine in excess acetone. The reaction was monitored and analyzed using HNMR. Based on HNMR spectra, there is 100% conversion when one drop of the reactant is in excess of the other reactant. This reaction was not conducted with an acidic catalyst, but the boric oxide in the glass vial or the coaxial system could have catalyzed the reaction.

Introduction The reaction of a ketone and a primary amine produces a ketoimine. An example of this reaction is the reaction of acetone and propylamine to produce N-propyl-2-propanimine.

Figure 1: Reaction of acetone and propylamine to produce N-propyl-2-propanimine

This reaction is typically done in the presence of an acidic catalyst, such as hydrogen chloride [[|1] ,[|2] ]. A new method has been developed that does not require the use of a catalyst. For this method, the reactants are combined in different ratios in Pyrex glass vials. The mixtures are then placed in a coaxial insert NMR tube with the deuterated solvent in an outer NMR tube. The coaxial system is composed of Pyrex [[|3]]. Each mixture is analyzed and observed using HNMR to determine if a product was formed.

Figure 2: Coaxial System composed of Pyrex [[|3]]

Results Five mixtures of different ratios of acetone and propylamine were prepared in glass vials. These five mixtures included reagent grade acetone, propylamine, 50/50 by volume acetone and propylamine, a drop of propylamine in excess acetone, and a drop of acetone in excess propylamine. The mole fractions and peak data can be found on the [|Array Table].

Based on this data, the product, N-propyl-2-propanimine, was produced during the 50/50 by volume reaction of acetone and propylamine at room temperature, a drop of acetone in excess propylamine, and a drop of propylamine in excess acetone. There was 100% conversion to the product within five hours when there was a drop of acetone in propylamine or a drop of propylamine in acetone. No catalyst was used during the reaction. After 24 hours, there was no change to the HNMR spectra and therefore, the reaction was completed within five hours.

The data also proves that there is an acetone impurity in the propylamine reagent bottle because N-propyl-2-propanimine is present in the HNMR spectrum for propylamine.

Discussion N-propyl-2-propanimine was formed from a mixture of 50/50 by volume acetone and propylamine with a ratio of 1:1 acetone to product at room temperature. The product was observed in the HNMR spectrum with a multiplet peak at 2.160ppm. A ketoimine, such as N-propyl-2-propanimine, is formed from the reaction of a ketone and primary amine. According to literature, this reaction is typically done in the presence of an acidic catalyst, such as hydrogen chloride [[|1] ,[|2] ]. However, the reaction was performed without an acidic catalyst by mixing the reactants in a Pyrex vial. Pyrex glass, or borosilicate glass, is composed of silica sand and boric oxide [[|4] ]. Boric oxide, which is an acidic component, can be an effective catalyst [[|5] ]. Therefore, the boric oxide component of Pyrex glass could have catalyzed the reaction. The experiment also proved that the impurity in the reagent grade acetone, which is present at 3.1ppm, is water. Based on the HNMR spectra, the peak shifts upfield during reactions with propylamine.

Conclusion HNMR can be used to monitor the reaction of acetone and propylamine with different mole fractions of reactants. This reaction forms N-propyl-2-propanimine, which is a ketoimine, when there is a 50/50 by volume mixture of the two reactants. The formation of this product is proven by the multiplet peak at 2.160ppm. The product was also formed during the reactions of one drop of acetone in excess propylamine and one drop of propylamine in excess acetone. For these reactions, there was 100% conversion to the product. The formation of the product is proven by the multiplet peaks at 2.125ppm and 2.57ppm, respectively. This reaction was not conducted with an acidic catalyst, but the boric oxide in the glass vial or the coaxial system could have catalyzed the reaction.

//Chemical Rediscovery Survey: Acetone, Propylamine, and Water// Another reaction that I have conducted is the reaction of acetone, propylamine, and water to see the effects that water has on imine formation. Based on the HNMR spectrum, N-propyl-2-propanimine and water were formed during the reaction of acetone and propylamine. After 24 hours at room temperature, the ratio of propylamine to N-propyl-2-propanimine was 2:1. The mixture of one drop of acetone and one drop of water in an excess of propylamine produced no product.

I plan on continuing to participate in the Chemical Rediscovery Survey to uncover discoveries and contribute to open science. This research expands my knowledge of lab techniques, instrumentation, and organic chemistry, which is preparing me for my future graduate study. I would like to continue to learn how to analyze HNMR and further analyze whether the glass vials are catalyzing the reactions or no acid catalyst is needed. The chemical rediscovery survey could have huge impacts on Open Science and contribute to the field of organic chemistry by changing how organic chemists view certain organic reactions.
 * Future Research Plans**