Chemical Properties
Clear colorless liquid
Uses
tert-Butyl ethyl malonate was used in the synthesis of polar ester-functionalized aliphatic polysulfone with remarkable thermal stability.
Uses
tert-Butyl ethyl malonate is used in the preparation of polar ester-functionalized aliphatic polysulfone. It is also a useful reagent for organic synthesis.
Synthesis Reference(s)
The Journal of Organic Chemistry, 39, p. 2114, 1974
DOI: 10.1021/jo00928a032
Synthesis
The general procedure for the synthesis of tert-butyl ethyl malonate from monoethyl malonate and tert-butanol was as follows: tert-butanol (2.8 mL, 37.8 mmol) was slowly added to a stirring solution of monoethyl malonate (5 g, 37.8 mmol) in acetonitrile (45 mL). Subsequently, a solution of DCC (8.58 g, 41.6 mmol) dissolved in acetonitrile (5 mL) was added dropwise to the reaction mixture over a period of 2 hours with continuous stirring. Upon completion of the reaction, the reaction mixture was filtered to remove insoluble by-products and the filtrate was concentrated to give 4.72 g (66% yield) of tert-butyl ethyl malonate. The product was analyzed by LCMS showing 189.11 (M + 1)+ with a purity of 93.4%.1H NMR (CDCl3) data were as follows: δ 4.2 (q, 2H), 3.3 (s, 2H), 1.4 (s, 9H), 1.3 (t, 3H).
Purification Methods
A likely impurity is monoethyl malonate; check IR for OH bands at 3330 br cm-1 . To ca 50g of ester add ice cold NaOH (50g in 200mL of H2O and 200g of ice). Swirl a few times (filter off ice if necessary), place it in a separating funnel and extract with 2 x 75mL of Et2O. Dry the extract (MgSO4) (since traces of acid decompose the t-Bu group of the ester, the distillation flask has to be washed with aqueous NaOH, rinsed with H2O and allowed to dry). Addition of some K2CO3 or MgO before distilling is recommended to inhibit decomposition. Distil it under reduced pressure through a 10cm Vigreux column (p 11). Decomposition is evidenced by severe foaming due to autocatalytic decomposition and cannot be prevented from accelerating except by stopping the distillation and rewashing the distillation flask with alkali again. [Breslow et al. J Am Chem Soc 66 1287 1944, Hauser et al. J Am Chem Soc 64 2714 1942, Strube Org Synth Coll Vol IV 417 1963, Stube Org Synth 37 35 1957, Beilstein 2 IV 1884.]
References
[1] Organic Letters, 2001, vol. 3, # 23, p. 3733 - 3735
[2] Journal of Organic Chemistry, 2002, vol. 67, # 25, p. 8975 - 8982
[3] Patent: US2009/239848, 2009, A1. Location in patent: Page/Page column 29
[4] Chemical and Pharmaceutical Bulletin, 1974, vol. 22, # 6, p. 1398 - 1404
[5] Bioorganic and Medicinal Chemistry Letters, 2003, vol. 13, # 16, p. 2659 - 2662
