N-(2-Cyanoethyl)-L-valine synthesis

Yield:51078-49-0 91%

Reaction Conditions:

Stage #1: L-valinewith potassium hydroxide in water at 20;
Stage #2: acrylonitrile in water at 0 - 5; for 4.5 - 5.5 h;

Steps:

1 EXAMPLE 1; N-(2-Cyanoethyl)-L-valine

L-valine (100 g) was suspended in water (100 [ML)] and an 85% solution of potassium hydroxide (56 g) in water (100 [ML)] was added at [20°C.] The reaction mixture was stirred at this temperature until the valine was fully dissolved. The solution was cooled to [0-5°C] and acrylonitrile (45 g) was added slowly over about 30 minutes at [0-5°C.] The reaction mixture was stirred at [0-5°C] for 4-5 hours. Water (250 [ML)] was added and the solution was acidified to pH 5 with concentrated hydro- chloric acid (about 70 [ML).] The suspension was then stirred at [0-5°C] for 1 hour and the solid was filtered off and washed with water (25 [ML).] The solid was dried at [60°C] under vacuum to give 137 g of N- (2-cyanoethyl)-L-valine (91% yield). m. p. [245-250°C] [; 13C-] NMR (50 MHz, [D20)] 0: 171. [76,] 117.27, 68. [34,] 42. [59,] 28.86, 17. [79,] 16. [91,] 14.48 ;'H- NMR (200 MHz, [D20)] [C] : 3.43 (d, [1 H),] 3.30 (t, 2H), 2.89 (t, 2H), 2.18-2. 09 (m, 1H), 0.93 (d, 3H), 0.89 (d, 3H) ; IR (KBr) cm-' : 3467, 2260, 1577 ; MS (El) : 171 [M+1], [130,] [125,] [84,] 81.

References:

WO2003/101971,2003,A1 Location in patent:Page 6