ethyl 2-(oxiran-2-yl)acetate

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

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

Conditions: temp:70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 5.8 g of 2-(1-methylethyl)-4-imidazolidinone hydrochloride ((5); R4 =H, R5 =isopropyl) (0.035 moles) are shaken in 10 ml water and treated with 2.4 g potassium carbonate (0.0174 moles). 4.5 g ethyl 3,4-epoxybutanoate and 6 ml acetone are added, and stirring is maintained for 45 h at 70° C. After evaporation, the residue is chromatographed on silica, eluting with 8:2 ethyl acetate/methanol. The main fractions are collected and evaporated. The oil that remains is taken up with ethyl acetate. After being left to stand overnight the white compound obtained is filtered: 1.3 g ethyl 2-(1-methylethyl)-4-oxo-1-imidazolidine-β-hydroxybutanoate m.p. 118°-122° C. 0.95 g of this compound (3.7 mmoles) are heated to boiling for 15 h in 4 ml DMF and 1 ml water. After evaporation in vacuo, the residue is taken up with methanol, and the solution is filtered. 0.37 g oxiracetam is obtained as a white crystalline powder, m.p. 167°-70° C. (63.2%). After evaporation the residue is chromatographed on silica eluting with 8:2 ethyl acetate/methanol The main fractions are collected evaporated After being left the white compound obtained is filtered After evaporation in vacuo the solution is filtered

Conditions: temp:70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 5.8 g of 2-(1-methylethyl)-4-imidazolidinone hydrochloride ((5); R4 =H, R5 =isopropyl) (0.035 moles) are shaken in 10 ml water and treated with 2.4 g potassium carbonate (0.0174 moles). 4.5 g ethyl 3,4-epoxybutanoate and 6 ml acetone are added, and stirring is maintained for 45 h at 70° C. After evaporation, the residue is chromatographed on silica, eluting with 8:2 ethyl acetate/methanol. The main fractions are collected and evaporated. The oil that remains is taken up with ethyl acetate. After being left to stand overnight the white compound obtained is filtered: 1.3 g ethyl 2-(1-methylethyl)-4-oxo-1-imidazolidine-β-hydroxybutanoate m.p. 118°-122° C. 0.95 g of this compound (3.7 mmoles) are heated to boiling for 15 h in 4 ml DMF and 1 ml water. After evaporation in vacuo, the residue is taken up with methanol, and the solution is filtered. 0.37 g oxiracetam is obtained as a white crystalline powder, m.p. 167°-70° C. (63.2%). After evaporation the residue is chromatographed on silica eluting with 8:2 ethyl acetate/methanol The main fractions are collected evaporated After being left the white compound obtained is filtered After evaporation in vacuo the solution is filtered

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

Procedure: In accordance with Scheme I, (S)-3-hydroxy-4-[[(4-methylphenyl)sulfonyl]oxy]butanoic acid methyl ester 2, (S)-3-hydroxy-4-iodobutanoic acid ethyl ester 3 and (S)=oxiraneacetic acid ethyl ester 4 are prepared from (S)-malic acid 1 using previously described methods [S. Saito et. al. Chem. Lett. 1389, (1984) and M. Larcheveque et. al. Tetrahedron Lett. 1781, 28 (1987)]. The esters 2, 3 and 4 are individually reacted with propargylamine in an alcohol solvent at temperatures ranging from room temperature to the reflux temperature of the solvent, preferably in the presence of an alkali metal carbonate, to produce (S)-4-hydroxy-1-(2-propynyl)-2-pyrrolidinone 5. Compound 5 is then reacted with an aryl or a (C1 -C6) carboxylic acid anhydride such as acetic anhydride in the presence of pyridine and preferably dimethylaminopyridine in an ether or a chlorohydrocarbon solvent, such as dichloromethane, to give the intermediate of general formula 6, for example, (S)-4-(acetyloxy)-1-(2-propynyl)- 2-pyrrolidinone.