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Example 1A; 2- (Acetylamino) butanoic acid; 163 g (1. 58 mol) 2-Aminobutanoic acid are dissolved in acetic acid, and 242 g (2.37 mol) acetic anhydride are added dropwise. The mixture is stirred for 2 h at 100C until completion of reaction, then the solution is evaporated to dryness in vacuo. The solid residue is suspended in ethyl acetate, filtered and washed with diethyl ether. Yield: 220 g (95.9%) IH-NMR (Methanol-d4): o/ppm 0.97 (t, 3 H), 1.65-1. 93 (m, 2 H), 1.99 (s, 3 H), 4.29 (q, 1 H) ppm.
95.9%
With acetic acid; at 100℃; for 2.0h;
Example 1A; 2- (Acetylamino) butanoic acid; 163 g (1. 58 mol) 2-Aminobutanoic acid are dissolved in acetic acid, and 242 g (2.37 mol) acetic anhydride are added dropwise. The mixture is stirred for 2 h at 100C until completion of reaction, then the solution is evaporated to dryness in vacuo. The solid residue is suspended in ethyl acetate, filtered and washed with diethyl ether. Yield: 220 g (95.9%) IH-NMR (CD30D) : 6 = 0.97 (t, 3H), 1.65-1. 93 (m, 2H), 1.99 (s, 3H), 4.29 (q, 1H) ppm.
95.9%
In acetic acid; at 100℃; for 2.0h;
163 g (1. 58mol) 2-aminobutanoic acid are dissolved in acetic acid, and 242 g (2.37 mol) acetic anhydride are added dropwise. The mixture is stirred for 2 h at 100C until completion of reaction, then the solution is evaporated to dryness in vacuo. The solid residue is suspended in ethyl acetate, filtered and washed with diethyl ether. Yield: 220 g (95.9%) 1H-NMR (Methanol-d4) : 8 = 0.97 (t, 3H), 1.65-1. 93 (m, 2H), 1.99 (s, 3H), 4.29 (q, 1H) ppm.
With acetic anhydride; In acetic acid; ethyl acetate;
EXAMPLE 1A 2-(Acetylamino)butanoic Acid 163 g (1,58 mol) 2-aminobutanoic acid are dissolved in acetic acid, and 242 g (2,37 mol) acetic anhydride are added dropwise. The mixture is stirred for 2 h at 100 C. until completion of reaction, then the solution evaporated to dryness in vacuo. The solid residue is suspended in ethyl acetate, filtered and washed with diethyl ether. Yield: 220 g (96%) 1H-NMR (Methanol-d4): delta=0,97 (t, 3H), 1,65-1,93 (m, 2H), 1,99 (s, 3H), 4,29 (q, 1H) ppm.
With acetic anhydride;
EXAMPLE 2A 2-(Acetylamino)butanoic acid 163 g (1.58 mol) of 2-aminobutyric acid are reacted analogously to Example 1A with 242 g (2.37 mol) of acetic anhydride to give 2-(acetylamino)butanoic acid. Yield: 220 g (95.9% of th.) 1H-NMR (methanol-d4): delta/ppm 0.97 (t, 3 H), 1.65-1.93 (m, 2 H), 1.99 (s, 3 H), 4.29 (q, 1 H).
14.5 g of N-acetyl-DL-2-aminobutyric acid was dissolved in 1 liter of water and the pH thereof was adjusted to 8.0 with LiOH. To the solution were added 83 mg of CoCl2.2H2 O and 21,750 units of a fungal acylase and reacted at 37C. When the L-2-aminobutyric acid produced was followed by a colorimetric determination using ninhydrin, it was found that about 100% conversion was attained in 17 hours.