ethyl 3-[(3-ethoxy-3-oxopropanoyl)amino]-3-methylbutanoate

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of sodium ethoxide, obtained from sodium metal (0.122 g, 5.55 mmol) in anhydrous ethanol (7 mL), a solution of ethyl 3-[(3-ethoxy-3-oxopropanoyl)amino]-3-methylbutanoate (1.2 g, 4.62 mmol) in dry toluene (7 mL) was added dropwise at room temperature, under stirring. The reaction mixture was heated at 80° C. for 2 hours then it was concentrated to reduced volume and the residue was dissolved in toluene (15 mL). The organic phase was extracted with water (40 mL), the aqueous phase was acidified to pH 2-3 with 1 N HCl and extracted with ethyl acetate (4×50 mL). The organic phase was washed with brine, dried over anhydrous sodium sulphate and concentrated to give ethyl 6,6-dimethyl-2,4-dioxopiperidine-3-carboxylate as a yellow solid (0.7 g, Y=71%) which was used for the next step without further purification. it was concentrated to reduced volume the residue was dissolved in toluene (15 mL) The organic phase was extracted with water (40 mL) extracted with ethyl acetate (4×50 mL) The organic phase was washed with brine dried over anhydrous sodium sulphate concentrated

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Ethyl 3-amino-3-methylbutanoate hydrochloride (0.87 g, 4.79 mmol) was suspended on methylene chloride (12 mL) and triethylamine (1.4 mL, 2.1 eq.). The mixture was cooled to 0° C. and treated dropwise with ethyl 3-chloro-3-oxopropanoate (0.64 mL, 1.05 eq.). The reaction was kept at room temperature for 2 hours, diluted with methylene chloride, washed with 1 N HCl and then with 5% NaHCO3, dried over Na2SO4 and evaporated to dryness to obtain ethyl 3-[(3-ethoxy-3-oxopropanoyl)amino]-3-methylbutanoate (1.2 g, Y=97%) as a red oil. washed with 1 N HCl with 5% NaHCO3, dried over Na2SO4 evaporated to dryness