2-(1-methyl-2-oxopyrrolidin-3-yl)acetaldehyde

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

Procedure: A solution of dimethylsulphoxide (1.7 ml) in dichloromethane (10 ml) was added dropwise over 5 min to a stirred solution of oxalyl chloride (1.0 ml) in dichloromethane (20 ml) at - 72° under nitrogen. The resultant solution was stirred at - 72° for 5 min then a suspension of 3-(2-hydroxyethyl)-1-methyl-2-pyrrolidinone (1.30 g) in dichloromethane (10 ml) and dimethylsulphoxide (1 ml; added to improve dissolution of the alcohol) was added dropwise over 8 min. The resultant cloudy solution was stirred at - 72° for 15 min then treated with triethylamine (7.0 ml). The resultant suspension was warmed to room temperature and stirred at room temperature for 1 h. The suspension was filtered. The residue was washed with ethyl acetate. The combined filtrate and washings were evaporated to give a semi-solid which was chromatographed using a mixture of ethyl acetate and methanol (5:1) as the eluent, to give the title compound (743 mg). added was added dropwise over 8 min stirred at room temperature for 1 h The suspension was filtered The residue was washed with ethyl acetate The combined filtrate and washings were evaporated to give a semi-solid which was chromatographed a mixture of ethyl acetate and methanol (5:1) as the eluent

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

Procedure: A solution of dimethylsulphoxide (1.7 ml) in dichloromethane (10 ml) was added dropwise over 5 min to a stirred solution of oxalyl chloride (1.0 ml) in dichloromethane (20 ml) at - 72° under nitrogen. The resultant solution was stirred at - 72° for 5 min then a suspension of 3-(2-hydroxyethyl)-1-methyl-2-pyrrolidinone (1.30 g) in dichloromethane (10 ml) and dimethylsulphoxide (1 ml; added to improve dissolution of the alcohol) was added dropwise over 8 min. The resultant cloudy solution was stirred at - 72° for 15 min then treated with triethylamine (7.0 ml). The resultant suspension was warmed to room temperature and stirred at room temperature for 1 h. The suspension was filtered. The residue was washed with ethyl acetate. The combined filtrate and washings were evaporated to give a semi-solid which was chromatographed using a mixture of ethyl acetate and methanol (5:1) as the eluent, to give the title compound (743 mg). added was added dropwise over 8 min stirred at room temperature for 1 h The suspension was filtered The residue was washed with ethyl acetate The combined filtrate and washings were evaporated to give a semi-solid which was chromatographed a mixture of ethyl acetate and methanol (5:1) as the eluent

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

Procedure: A solution of dimethylsulphoxide (1.7 ml) in dichloromethane (10 ml) was added dropwise over 5 min to a stirred solution of oxalyl chloride (1.0 ml) in dichloromethane (20 ml) at - 72° under nitrogen. The resultant solution was stirred at - 72° for 5 min then a suspension of 3-(2-hydroxyethyl)-1-methyl-2-pyrrolidinone (1.30 g) in dichloromethane (10 ml) and dimethylsulphoxide (1 ml; added to improve dissolution of the alcohol) was added dropwise over 8 min. The resultant cloudy solution was stirred at - 72° for 15 min then treated with triethylamine (7.0 ml). The resultant suspension was warmed to room temperature and stirred at room temperature for 1 h. The suspension was filtered. The residue was washed with ethyl acetate. The combined filtrate and washings were evaporated to give a semi-solid which was chromatographed using a mixture of ethyl acetate and methanol (5:1) as the eluent, to give the title compound (743 mg). added was added dropwise over 8 min stirred at room temperature for 1 h The suspension was filtered The residue was washed with ethyl acetate The combined filtrate and washings were evaporated to give a semi-solid which was chromatographed a mixture of ethyl acetate and methanol (5:1) as the eluent