Ethyl sodium phthalimidomalonate

B. Ethyl I -Methyllhiol- -phthalimidopropane-, 3 -dicarboxylate. —A mixture of 85 g. (0.26 mole) of ethyl sodium phthalimidomalonate and 43 g. (0.39 mole) of, fl-chloroethyl methyl sulfide (p. 18) is heated in an oil bath at 160-165° in a i-l. three-necked flask, fitted with a condenser, a thermometer, and a stoppered... 

The ethyl sodium phthalimidomalonate crystallizes with 1.5 molecules of alcohol, which is removed only on heating above 140° in vacuo. 

Ethyl pentadecylate, 16, 37 Ethyl pentanehexacarboxylate, 10, 59 Ethyl phenylacetate, 16, 33 Ethyl -phenylacetoacetate, 18, 36 Ethyl -y-phenylbctyrate, 18, 25, 26 Ethyl phenylcyanopyruvate, 11, 40 Ethyl /J-phenylethyl ketone, 16, 49 Ethyl phenylmalonate, 16, 33 18, 84 Ethyl phenyloxaloacetate, 16, 33 Ethyl phthalimidomalonate, 14, 58 Ethyl pjmelate, 11, 42 17, 91 Ethyl propanetetracarboxylate, 10, 58 Ethyl propionate, 17, 34 Ethyl tso-propylmalonate, 11, 20, 21 Ethyl salicylate, 10, 51 11, 43 Ethyl sebacate, 14, 20 Ethyl sodium phthalimidomalonate, 14, 58... 

Serine has been prepared by the Strecker method from glycol-aldehyde 1 and from ethoxyacetaldehyde,2 3 by the condensation of ethyl formate with ethyl hippurate followed by reduction and hydrolysis,4 5 from the reaction product of chloromethyl ether with ethyl sodium phthalimidomalonate,6 and by amination of a-bromo-/3-methoxypropionic acid with subsequent demethyla-tion.7... 

A. Ethyl Sodium Phthalimidomalonate.—To a solution of 9.2 g. (0.4 gram atom) of sodium in 300 cc. of absolute alcohol at 600 is added, with efficient stirring, 126 g. (0.41 mole) of ethyl phthalimidomalonate (Org. Syn. Coll. Vol. 1, 266). The mixture is rapidly chilled to o° and the crystalline product filtered at once by suction and washed successively with two 200-cc. portions of absolute alcohol and two 200-cc. portions of ether. After first drying in a vacuum desiccator and then heating for eight hours under 15 mm. pressure in a flask suspended in an oil bath at 145-155° (Note x), it weighs 108-ixi g. (82-85 Per cent the theoretical amount). 

Diethyl sodium phthalimidomalonate (Barger and Weichselbaum, Organic Syntheses, 1943, Coll. Vol. II, 3B4) (6.52 g) was dissolved in boiling methyl ethyl ketone (BO ml) and a solution of p-nitrobenzyl chloride (3.44 g 1.0 mol) in the same solvent (20 ml) was added. Sodium iodide (ca 0.5 g) dissolved in hot methyl ethyl ketone (10 ml) was introduced, and produced an immediate precipitation. The mixture was refluxed for 1.5 hours, cooled, filtered, evaporated under vacuum and the residual gum crystallized from ethanol. The di-ethyl-p-nitrobenzyl-phthalimidomalonate formed colorless prisms (B8%), MP 103° to 105°C, sharpening to 104° to 105°C on recrystallizing from ethanol. 

A. Triethyl a-phtkalimidoethane-a,a, -tricarboxylate. Three hundred and twenty-seven grams (1.0 mole) of diethyl sodium phthalimidomalonate and 735 g. (6.0 moles) of ethyl chloro-acetate (b.p. 144-145°) are placed in a 2-1. Claisen flask fitted with a reflux condenser and rubber stoppers. The mixture is heated under reflux in an oil bath at 150-160° for 2.25 hours. The excess ethyl chloroacetate is removed by distillation at 30 mm. until the heating bath temperature reaches 150° and no more distillate is obtained (Note 1). The brown residual mass is... 

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