(S)-N-Boc-3-Bromophenylalanine synthesis

Yield:82278-73-7 98%

Reaction Conditions:

with sodium hydrogencarbonate in 1,4-dioxane;water

Steps:

2; 2A; 2B Example 2
[00121] t-Butylcarbamate (Boc) protection of the amino group of bromophenylalaninewas accomplished, using sodium bicarbonate (3 equivalents), t-butyl dicarbonate (Boc2O, 1.1equivalent) in dioxane and water, to obtain compound 7 in 98% yield. A methyl sulfone functionality was introduced by treating the bromo compound 7 with copper iodide (0.4 equivalents), cesium carbonate (0.5 equivalents), L-proline (0.8 equivalents), and the sodium salt of methanesulfinic acid (3.9 equivalents) in dimethylsulfoxide (DMSO) at 95-100°C for a totalof 9 hours, with two further additions of copper iodide (0.2 equivalents) and L-proline (0.4 equivalents) during that period. Compound 8 was isolated in 96% yield. The carboxylic acid of compound 8 was converted to the benzyl ester, compound 9, in 99% yield, using benzyl alcohol (1 .1 equivalent), dimethylaminopyridine (DMAP, 0.1 equivalent) and N-(3 - dimethylaminopropyl)-N-ethylcarbodiimide (EDC, 1.0 equivalent). The amino group ofcompound 9 is deprotected by adding a 4N solution of HC1 in dioxane to compound 9 at 0°C in methylene chloride. The HC1 salt of the free amino species, compound 10 was isolated in 94% yield.

References:

SARCODE BIOSCIENCE INC.;ZELLER, James, Robert;VENKATRAMAN, Sripathy;BROT, Elisabeth, C.A.;IYER, Subashree;HALL, Michael WO2014/18748, 2014, A1 Location in patent:Paragraph 00120; 00121; 00122; 00123; 00124; 00125

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