DA 1 - Synthesis of 1,2,3,4- by Diels-Alder Reaction...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
ONO DME, heat CO 2 N N BENZYNE Ph Ph Ph Ph heat Ph Ph Ph Ph O - CO 2 - CO O N 2 CO 2 H NH 2 Ph Ph Ph Ph Anthranilic acid Tetraphenylcyclopentadienone 1, 2, 3, 4-tetraphenylnaphthalene Synthesis of 1,2,3,4-tetraphenylnaphthalene by Diels-Alder Reaction between Tetraphenylcyclopentadienone and Benzyne Tianran Li TA: Karen Beckman Chem 2311, Section 5 July 5 th , 2011 Purpose: The purpose of this experiment is to synthesize benzyne formed by anthranilic acid and isoamyl nitrite in situ, and to use benzyne synthesized (intermediate, as dienophile) and tetraphenylcyclopentadienone (as diene) for preparing 1,2,3,4-tetraphenylnaphthalene through Diels- Alder reaction. The final product is crystallized from its ethanol solution and collected by vacuum filtration. Melting point range was observed to determine the synthesized 1,2,3,4- tetraphenylnaphthalene’s purity. 1 H NMR spectroscopy of the product was obtained to characterize and identify 1,2,3,4-tetraphenylnaphthalene and its purity. Reaction Scheme: Mechanism: Key features of this Diels-Alder reaction are: a. formation of benzyne intermediate from diazonium salt through reaction between anthranilic acid and isoamyl nitrite; b. benzyne ring was trapped onto the diene, tetraphenylcyclopentadienone, as soon as it was generated. A key reactive intermediate of Diels-Alder reaction then formed and rearranged for aromatization. After loss of carbon monoxide from the reactive intermediate, 1,2,3,4-tetraphenylnaphthalene would be obtained.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
CO 2 H NH 2 CO 2 H N H H H ONO CO 2 NH 2 + O N O CO 2 N N OH R-OH H CO 2 N N O H H ROH CO 2 N N O H R OH H CO 2 N N O H H R-OH -HOR CO 2 N N O H H -H 2 O C O O N N N N O O -CO 2 -N 2 heat Key reactive intermeidate diazonium salt benzyne proton transfer Benzyne Formation Ph Ph Ph Ph Ph Ph Ph Ph O + heat Ph Ph Ph Ph O heat -CO concerted mechanism involving 6 e Diels-Alder Reaction (Pi electrons) Ph Ph Ph Ph O Enlarged intermediate structure and arrow flows of Diels-Alder Reaction are shown below: OR (alternative perspective) Procedure: The procedure followed was as is describes in “Laboratory Manual for Organic Chemistry 2311”, Tenth Edition , Jane E. Wissinger , Thomson Custom Publishing, Mason, Ohio, 2011 , pp. 67-68. No modification of procedure was performed. The lab lasted for 1 day, approximately 2 hours.
Background image of page 2
Table 1. Reagent Table: anthranilic acid 1,2- dimethoxyet hane (DME) Isoamyl nitrite Tetraphenylcycl opentadienone Ethanol 1,2,3,4- tetraphenylnap hthalene Mol Wt. (g/mol) 137.14 90.12 117.14 384.48 46.07 432.55 Grams (g) 0.121 3.64686 0.1744 0.249 1.17 0.222 mL x 4.2 0.2 x 1.5 x mmoles 0.882 40.47 1.489 0.648 25.40 0.513 Density, g/mL 1.412 0.8683 0.872 1.233 0.78 1.124 bpt/mpt, °C 312/144-148 83/-58 99/- 617.1/217-220 78.3/- 114.1 486.1/199-201 Solubility Slightly soluble in water, sol. in DME Miscible in water Slightly soluble in water Insoluble In water, soluble in DME Soluble in water Soluble in water, soluble in ethanol Hazards Irritant Hamful if inhaled, irritant,
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 07/20/2011 for the course CHEM 2311 taught by Professor Wissenger during the Spring '08 term at Minnesota.

Page1 / 6

DA 1 - Synthesis of 1,2,3,4- by Diels-Alder Reaction...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online