Cyclopentadiene Recovery

986 WordsApr 27, 20114 Pages
Maleic anhydride underwent the Dials-Alder reaction with distilled cyclopentadiene as the dienophile. The reaction was a cycloaddition which produced cis-Norbornene-5,6-endo-dicarboxylic Anhydride surface. (1) Product one had a mass of 9.351 grams and product two had a mass of 9.572 grams. The theoretical yield was found to be 10.047 grams, which makes the percent yield to be 93.07%. Melting Points were found to confirm the purity of the product. Product one had a melting point of 163.7-164.8°C. Product two had a melting point of 162.2-163.9°C. IR Spectroscopy (nujol) are carbonyl peaks (1773.4 cm-1), Sp3 C-H peaks (2921.5 cm-1), Sp2 C-H (3000 cm-1). The carbonyl peaks prove the presence of an acid anhydride. H’NMR (CDCL3)…show more content…
Methylene chloride is added to the flask with the diester. The seperatory funnel is attached to the flask with 1.0 M bromine inside. Bromine is added to ester mixture drop by drop until the solution stays a yellow color. After ten minutes a cyclohexene and methylene chloride mixture is added drop by drop to remove the excess bromine. Ester solution is placed on the rotary evaporator at 45°C. Ethanol was added to the product. Solution was cooled in an ice bath for thirty minutes and crystals began to form. Solution was vacuum filtered with a Hirsch funnel. The mass of the product was 0.47 g. MP 70.1-75.3°C The theoretical yield was .74 g. This makes the percent yield 64%. The expected melting point was 123-125°C. The diacid was not the product formed. With IR, HNMR, and CNMR data the identity of the final product was found. IR (neat) 2989.8 and 2955.7 (Sp3 C-H), 1785.8 (Lactone ester), 1735.8 (ester). 1H NMR (CDCL3) 5.073 ppm (d, 1H), 4.991 ppm (d, 1H), 4.637 ppm (d, 1H), 4.599 ppm (d, 1H), 3.764 ppm (s, 3H), 3.364 ppm ( m, 1H), 3.130 ppm (m,1H), 2.948 ppm (d, 1H), 2.558 ppm (m, 2H), 2.363 ppm ( m, 1H), 1.934 ppm (s, 1H), 1.728 ppm (s, 1H). 13C NMR (CDCL3) 177.037 ppm, 171.388 ppm, 88.171 ppm, 53.125 ppm, 50.270 ppm, 49.297 ppm, 49.328 ppm, 49.040 ppm, 41.317 ppm, 36.441

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