Methylamine → 4-{[({[(2S)-4-(3,4-dichlorobenzyl)morpholin-2-yl]methyl}amino)carbonyl]amino}-N-methylbutanamide

N,N′-carbonyldiimidazole (0.0132 g) was added to a stirred solution of Intermediate 26 (0.030 g) in N,N-dimethylformamide (2 ml), and the mixture stirred at 22° C. under nitrogen for 40 min. Methylamine (2.0M solution in tetrahydrofuran, 0.102 ml) was added, and stirring was continued at 22° C. for 17 h. The mixture was applied directly to a sulphonic acid ion exchange cartridge (2 g Isolute SCX), and eluted with methanol followed by 10% 0.880 ammonia in methanol to give a gum (0.042 g). Purification by chromatography on silica gel (1 g Varian Bond Elut cartridge), eluting with chloroform, ether, ethyl acetate, acetone, and methanol, gave a gum (0.025 g), which was further purified by mass directed preparative HPLC to give the title compound as a colourless gum (7.2 mg).