sodium;3-methyl-2-oxobutanoate

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

Procedure: A mixture of 3-methyl-2-oxobutyric acid sodium salt (1.46 g) and L-alanyl-L-proline (0.40 g) was treated with sodium cyanoborohydride (0.41 g) as described above. Crude N-(1-carboxy-2-methylpropyl)-L-alanyl-L-proline (0.45 g) was obtained by elution from ion-exchange resin. The product melted at 131°-142°. The nmr spectrum shows complex absorption in the 4.6 to 3.3 region, a broad multiplet centered at 2.2 and doublets at 1.65 and 1.1 ppm.

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

Procedure: A mixture of 3-methyl-2-oxobutyric acid sodium salt (1.46 g) and L-alanyl-L-proline (0.40 g) was treated with sodium cyanoborohydride (0.41 g) as described above. Crude N-(1-carboxy-2-methylpropyl)-L-alanyl-L-proline (0.45 g) was obtained by elution from ion-exchange resin. The product melted at 131°-142°. The nmr spectrum shows complex absorption in the 4.6 to 3.3 region, a broad multiplet centered at 2.2 and doublets at 1.65 and 1.1 ppm.

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

Procedure: A mixture of 3-methyl-2-oxobutyric acid sodium salt (1.46 g) and L-alanyl-L-proline (0.40 g) was treated with sodium cyanoborohydride (0.41 g) as described above. Crude N-(1-carboxy-2-methylpropyl)L-alanyl-L-proline (0.45 g) was obtained by elution from ion-exchange resin. The product melted at 131°-142°. The nmr spectrum shows complex absorption in the 4.6 to 3.3 region, a broad multiplet centered at 2.2 and doublets at 1.65 and 1.1 ppm.