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Process for preparation of tert-Butyl ((2S)-4-methyl-1-(2-methyloxiran-2-yl)-1-oxopentan-2-yl)carbamate

IP.com Disclosure Number: IPCOM000239297D
Publication Date: 2014-Oct-28
Document File: 2 page(s) / 62K

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Process for preparation of tert-Butyl ((2S)-4-methyl-1-(2-methyloxiran-2-yl)-1-oxopentan-2-yl)carbamate

Described herein below, is an improved process for preparation of tert-Butyl ((2S)-4-methyl-1-(2-methyloxiran-2-yl)-1-oxopentan-2-yl)carbamate (referred to as compound B)

Experimental procedure:

Example 1

Compound A (tert-butyl ((2S)-1-hydroxy-4-methyl-1-(2-methyloxiran-2-yl)pentan-2-yl)carbamate) was dissolved in acetonitrile/water mixture (solvent ratio 10:1 to 1:10; 10 volumes). KI (0.25 molEq), K2CO3 (2 molEq) and I2 (1-2 molEq) were added. Reaction mixture was warmed up to 50 °C and stirred overnight. Resulting reaction mixture was cooled to room temperature, diluted with methylene chloride, treated with Na2S2O3 or Na2SO3 solution and washed with water, dried over anhydrous MgSO4 and evaporated to dryness yielding Compound B, tert-Butyl ((2S)-4-methyl-1-(2-methyloxiran-2-yl)-1-oxopentan-2-yl)carbamate. The residue was recovered with ethanol (3 volumes) and the product precipitated by addition of water (3 volumes). The material was isolated by filtration and dried in oven for 12 hours under vacuum to afford compound B in crystalline form.

Example 2

Compound A (tert-butyl ((2S)-1-hydroxy-4-methyl-1-(2-methyloxiran-2-yl)pentan-2-yl)carbamate) was dissolved t-BuOH (5-10 volumes). KI (0-0.25 molEq), K2CO3 (2-3 molEq) and I2 (1-2 molEq) were added. Reaction mixture was warmed up to 50 °C and stirred overnight. Resulting reaction mixture was cooled to room temperature, dil...