Benzoin

Benzoin has a secondary alcohol as well as a ketone functional group which is oxidized into benzil with nitric acid. Oxidation of alpha-hydroxyketone occurs to form alpha-diketone. Hydroxyl group adds as a nucleophile on the carbonyl carbon of alcohol with nitric acid to form organic nitrate. Nitric acid is protonated to form benzil. Rearrangement of alpha-diketone benzil occurs. Hence, the addition of potassium hydroxide to benzil yields a carboxylic salt. Hydrochloric acid added to the potassium

synthesis of the final product, tetraphenylcyclopentadienone. The first step of the experiment was the condensation of benzaldehyde to yield benzoin. Thiamine catalyst along with water and ethanol were added to the benzaldehyde, then NaOH was added until the solution turned yellow. After recrystallization, the product was benzoin. Step two was the oxidation of benzoin to benzil.

carried out was an oxidation of benzoin to benzil using a recyclable copper catalyst, cupric acetate. The cupric acetate acted as an electron acceptor in a redox type reaction. The benzoin donated an electron to cupric acetate and formed the Cu+ ion while becoming a benzoin radical cation. The benzoin radical cation lost a hydrogen to the Cu+ ion forming acetic acid. Another redox cycle between Cu2+ and the benzoin radical took place, forming a second Cu+ ion and the benzoin cation lost a proton to another

experiment will involve the conversion of Benzoin into Benzil through oxidation using nitric acid. Benzoin was synthesized in a previous experiment using two Benzaldehyde molecules and thiamine hydrochloride as a catalyst. The reaction is known as a Benzoin condensation reaction. This experiment utilized a wide a variety of techniques including reflux; filtering using a Buchner funnel; a melting point analysis; and an IR spectroscopy. The total yield for Benzoin was 3.506 grams which resulted in a

SYNT m o d u l a r · l a b o r a t o r y · p r o g r a m · i n · publisher: H. A. Neidig c h e m i s t r y 738 organic editor: Joe Jeffers Copper-Catalyzed Oxidation of Benzoin to Benzil prepared by Carl T. Wigal, Lebanon Valley College PURPOSE OF THE EXPERIMENT Oxidize benzoin to benzil using ammonium nitrate and copper(II) ion as a catalyst, monitoring the reaction by thin-layer chromatography. Characterize the product using melting point measurement and infrared spectroscopy. EXPERIMENTAL

Abstract – Dilantin is an antiepileptic drug by acting on the nervous system and this lab synthesized pure Dilantin through a multistep process. The first step involves using the coenzyme, thiamine, as a catalyst to synthesize benzoin. Benzoin is oxidized to benzil using NH4NO3 to regenerate amounts of cupric acetate, followed by reaction with urea in a base to yield Dilantin. Experimental physical properties and spectral data were analyzed to show relatively pure Dilantin synthesized. Introduction:

extracted benzoic acid and measure the MP. 11) Dry out the methylene chloride solution that contain the benzoin and the dibromobenzene by the use of anhydrous sodium sulfate. 12) Pipet the remaining methylene chloride to a new beaker. Place the flask in hot water bath, and boil the methylene chloride out, leaving the benzoin and the dibromobenzene . 15) to separate the benzoin and the dibromobenzene, a crystallization should be performed 16) Heat some of the hexane to boiling and

mainly due to the fact that benzaldehyde is a cheap starting material and is very resourceful. The overall objective of the experiment was to obtain benzilic acid with the use of the multistep synthesis procedure which consist of a benzoin condensation, oxidation of benzoin, and a final molecular rearrangement of benzil. This is a fairly long experiment

added as a workup step to remove the most acidic hydrogen at the carbon center. It is this step where the role of the carbonyl is reversed with carbon achieving a nucleophilic state. The nucleophilic carbon can attack another benzaldehyde forming a benzoin compound. Through work up steps the cyanide catalyst is removed leaving behind the final

are the peaks present in the experimental samples that support the pure identity of the product. General observations during and after procedures were noted and are displayed above. Figure 4. IR spectra of benzaldehyde Figure 5. IR spectra of benzoin