Cl[CH2:2][C:3]1[N:7]=[C:6]([CH2:8][CH2:9][C:10]([OH:12])=[O:11])[O:5][N:4]=1.CN(C)C=O.[NH:18]1[CH2:23][CH2:22][O:21][CH2:20][CH2:19]1.[OH-].[Na+:25]>CO>[N:18]1([CH2:2][C:3]2[N:7]=[C:6]([CH2:8][CH2:9][C:10]([O-:12])=[O:11])[O:5][N:4]=2)[CH2:23][CH2:22][O:21][CH2:20][CH2:19]1.[Na+:25]A 25 mL, one-neck, round bottomed flask equipped with a magnetic stirrer was charged with 3-(3-chloromethyl-1,2,4-oxadiazol-5-yl)propionic acid (1.48 g, 7.77 mmol), dimethylformamide (4 mL) and morpholine (2.0 g, 22.9 mmol). The reaction mixture was then stirred for 4 h at ambient temperature. The resulting suspension was filtered, and the filter cake was washed with ether and dried to afford 2.52 g of the crude product. A portion (1.49 g) of this material was dissolved in methanol (6 mL) and treated with sodium hydroxide (399 mg, 9.98 mmol). After 1 h, the reaction mixture was concentrated to dryness under vacuum, and then triturated with ethyl acetate. The precipitate was filtered and dried under reduced pressure affording a 68% yield of sodium 3-[3-(morpholin-4-ylmethyl)-1,2,4-oxadiazol-5yl]propionate, contaminated with a small amount of sodium acetate, as a white solid. This material was used directly. m.p. 155-161° C. (dec.); 1H NMR (DMSO-d6) δ (ppm) 3.56 (m, 6H), 2.98 (t, 2H,J=7.2 Hz), 2.46 (t, 4H,J=4.3 Hz), 2.36 (t, 2H,J=7.2 Hz): m/z=263 (M−Na).
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