methyl 5-amino-5-oxopentanoate

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

Procedure: Combine 2-bromo-2′-nitroacetophenone (10.4 g, 42.6 mmol) with 4-carbamoyl-butyric acid methyl ester (12.2 g, 84.1 mmol) and heat the neat mixture in a sealed vessel at 120-150° C. for about 4-6 h. Cool the mixture, transfer to a round bottom flask with methanol and concentrate. Partition the residue between water and EtOAc. Dry the combined EtOAc extracts over Na2SO4 and concentrate. Initial chromatography over silica gel (EtOAc/CH2Cl2) followed by a second chromatography over silica gel (Hex/EtOAc) allowed for recovery of 4-[4-(2-nitro-phenyl)-oxazol-2-yl]-butyric acid methyl ester (3.05 g, 25%). MS (ES): (M+1)+ 291.1, 292.2 m/z. concentrate Partition the residue between water and EtOAc Dry the combined EtOAc concentrate

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

Procedure: 6.1 Ammonia is passed into 350 ml of cold THF for 30 minutes. 30 g of methyl 4-chlorocarbonylbutyrate are then added dropwise, with ammonia continuing to be passed in at the same time. The crystals which deposit are separated off, and the residue is boiled a number of times with ethyl acetate. The combined filtrates are distilled off, and the residue is recrystallised from ethyl acetate, giving 23.4 g of methyl 4-aminocarbonylbutyrate (“FA”), m.p. 80°. The crystals which deposit are separated off The combined filtrates are distilled off the residue is recrystallised from ethyl acetate

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

Procedure: Combine 2-bromo-2′-nitroacetophenone (10.4 g, 42.6 mmol) with 4-carbamoyl-butyric acid methyl ester (12.2 g, 84.1 mmol) and heat the neat mixture in a sealed vessel at 120-150° C. for about 4-6 h. Cool the mixture, transfer to a round bottom flask with methanol and concentrate. Partition the residue between water and EtOAc. Dry the combined EtOAc extracts over Na2SO4 and concentrate. Initial chromatography over silica gel (EtOAc/CH2Cl2) followed by a second chromatography over silica gel (Hex/EtOAc) allowed for recovery of 4-[4-(2-nitro-phenyl)-oxazol-2-yl]-butyric acid methyl ester (3.05 g, 25%). MS (ES): (M+1)+ 291.1, 292.2 m/z. concentrate Partition the residue between water and EtOAc Dry the combined EtOAc concentrate

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

Procedure: Combine 2-bromo-2′-nitroacetophenone (10.4 g, 42.6 mmol) with 4-carbamoyl-butyric acid methyl ester (12.2 g, 84.1 mmol) and heat the neat mixture in a sealed vessel at 120-150° C. for about 4-6 h. Cool the mixture, transfer to a round bottom flask with methanol and concentrate. Partition the residue between water and EtOAc. Dry the combined EtOAc extracts over Na2SO4 and concentrate. Initial chromatography over silica gel (EtOAc/CH2Cl2) followed by a second chromatography over silica gel (Hex/EtOAc) allowed for recovery of 4-[4-(2-nitro-phenyl)-oxazol-2-yl]-butyric acid methyl ester (3.05 g, 25%). MS (ES): (M+1)+ 291.1, 292.2 m/z. concentrate Partition the residue between water and EtOAc Dry the combined EtOAc concentrate

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

Procedure: Combine 2-bromo-2′-nitroacetophenone (10.4 g, 42.6 mmol) with 4-carbamoyl-butyric acid methyl ester (12.2 g, 84.1 mmol) and heat the neat mixture in a sealed vessel at 120-150° C. for about 4-6 h. Cool the mixture, transfer to a round bottom flask with methanol and concentrate. Partition the residue between water and EtOAc. Dry the combined EtOAc extracts over Na2SO4 and concentrate. Initial chromatography over silica gel (EtOAc/CH2Cl2) followed by a second chromatography over silica gel (Hex/EtOAc) allowed for recovery of 4-[4-(2-nitro-phenyl)-oxazol-2-yl]-butyric acid methyl ester (3.05 g, 25%). MS (ES): (M+1)+ 291.1, 292.2 m/z. concentrate Partition the residue between water and EtOAc Dry the combined EtOAc concentrate

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

Procedure: 6.1 Ammonia is passed into 350 ml of cold THF for 30 minutes. 30 g of methyl 4-chlorocarbonylbutyrate are then added dropwise, with ammonia continuing to be passed in at the same time. The crystals which deposit are separated off, and the residue is boiled a number of times with ethyl acetate. The combined filtrates are distilled off, and the residue is recrystallised from ethyl acetate, giving 23.4 g of methyl 4-aminocarbonylbutyrate (“FA”), m.p. 80°. The crystals which deposit are separated off The combined filtrates are distilled off the residue is recrystallised from ethyl acetate