Yield:162537-11-3 100%

Reaction Conditions:

with sodium hydroxide in 1,4-dioxane;water; pH=8 - 9 at 60; for 18 h;

Steps:

8.1
Step 1: Synthesis of (S)-2-(methoxycarbonylaniino)-3,3-dimethylb tanoic acid:A stirred solution of (S)-2-amino-3,3-dimethylbutanoic acid (about 5.0 g, 38. 16 mmol) in Dioxane (about 20 ml) and sodium hydroxide (2N, 62 ml, P^H = 8-9) at about 0 °C, methychlroformate (about 5.88 ml, 76.33 mmol) was added drop wise and stirred at about 60 °C for about 18 hours. The reaction mixture was cooled to room temperature, extracted with DCM, the aqueous layer was separated and acidified with I N HCl. The resulting solution was extracted with EtOAc, dried over Na₂S0₄ and the solvent was evaporated under reduced pressure. The resulting crude was stirred in hexane and decants to afford the title compound as a solid. Wt: 8.5 g: Yield: quantitative; NMR (300 MHZ, CDCI₃): δ 5.25 (d, 1 H, J = 10.5 Hz), 4. 19(d, 1 H, J = 9.6 Hz) 3.70 (s, 3H), 1 .03 (s, 9H); Mass: [M- l ]^' 188 ( 100%); IR ( Br, cm ¹ ): 3379, 2974, 1727, 1688, 1546, 1466, 1332, 1263. 121 1 , 1070, 1034, 1018, 843, 696.

References:

HETERO RESEARCH FOUNDATION;PARTHASARADHI REDDY, Bandi;VAMSI KRISHNA, Bandi;MANOHAR SHARMA, Vedula;RATHNAKAR REDDY, Kura;MADHANMOHAN REDDY, Musku WO2011/80562, 2011, A1 Location in patent:Page/Page column 34

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