(S)-1-N-CBZ-PIPERAZINE-2-CARBOXYLIC ACID METHYL ESTER synthesis

Yield:314741-63-4 100%

Reaction Conditions:

Stage #1: 1-benzyl 4-(tert-butyl) 2-methyl (2S)-piperazine-1,2,4-tricarboxylatewith trifluoroacetic acid for 2 h;
Stage #2: with sodium hydrogencarbonate in water;ethyl acetate;

Steps:

24.a Example 24. [9aS, 3S]-3-(6-methoxyquinolin-4-yl)-8-heptylhexahydropyrazino [2,1-c][1,4]oxazin-3(4H)-one (a) [2S]-1-Benzyloxycarbonyl-2-methoxycarbonylpiperazine

Example 1(b) (3.6g, 9.5mmol) was dissolved in trifluoroacetic acid (50ml).. After 2h the solution was evaporated to dryness.. The residue was partitioned between ethyl acetate and saturated aqueous sodium bicarbonate solution.. The ethyl acetate extract was dried and evaporated giving the title compound as a yellow oil(2.6g,100%). MS (+ve ion electrospray) m/z 279 (MH+).

References:

EP1187828,2004,B1 Location in patent:Page 19