Diethyl phenylmalonate explained

Diethyl phenylmalonate is an aromatic malonic ester used in the synthesis of moderate to long lasting barbiturates such as phenobarbital.^[1]

Chemical synthesis

Unlike other malonic esters that are derived via malonic ester synthesis, diethyl phenylmalonate is typically indirectly derived via a Claisen condensation with diethyl oxalate and ethyl phenylacetate followed by decarbonylation.^[2] This indirect method is often used because aryl halides are relatively weaker electrophiles than alkyl halides and thus poorly alkylate diethyl malonate.^[3] Methods using Caesium carbonate and copper(I) iodide have been developed to overcome this difficulty however.^[4]

Notes and References

1. Wollweber. Hartmund . Hypnotics . Ullmann's Encyclopedia of Industrial Chemistry . 2000 . 11 . 10.1002/14356007.a13_533. 3527306730 .
2. Meyer. G. M.. Levene. P. A.. Diethyl phenylmalonate. Organic Syntheses. 1936. 16. 33. 10.15227/orgsyn.016.0033.
3. Book: Furniss, Brian . Hannaford, Antony . Smith, Peter . Tatchell, Austin . Vogel's Textbook of Practical Organic Chemistry 5th Ed.. 1996. Longman Science & Technical. London. 9780582462366. 1174–1179.
4. Hennessy. Edward J.. Buchwald. Stephen L.. A General and Mild Copper-Catalyzed Arylation of Diethyl Malonate. Organic Letters. 2002. 4. 2. 269–272. 10.1021/ol017038g. 11796067.