NC 2300 synthesis

Yield:221144-20-3 87.9%

Reaction Conditions:

with sodium carbonate in water;acetone at 20 - 50; for 3 h;Product distribution / selectivity;

Steps:

8

(2S,3S)-3-[[(1S)-1-isobutoxymethyl-3-methylbutyl]-carbamoyl]oxirane-2-carboxylic acid (48.59 g) was dissolved in acetone (245 mL), and sodium carbonate (8.51 g) dissolved in water (32.9 mL) was slowly added. The solution was stirred at room temperature to 50°C for three hours until the deposited inorganic salt was dissolved. While the temperature was kept, acetone (200 mL) was dropped and a seed crystal was placed in the solution, and then the solution was stirred for 30 minutes. Acetone (510 mL) was again dropped, and the solution was stirred for 1 hour while the temperature was kept. While the solution was gradually cooled to room temperature, it was stirred overnight. The precipitated crystalline product was collected by filtration, washed with a mixture of 3% water-acetone (70 mL), dried in air to obtain white solid sodium (2S,3S)-3-[[(1S)-1-isobutoxymethyl-3-methylbutyl]carbamoyl]oxirane-2-carboxylate (46.1 g, 87.9%). The NMR data of the solid product were the same as those in Example 9.

References:

EP1619190,2006,A1 Location in patent:Page/Page column 8-9