4-((4-tert-Butoxycarbonyl)piperazin-1-yl)methyl)phenylboronic acid synthesis

Yield:1190095-10-3 87.4%

Reaction Conditions:

Stage #1: 4-formylphenylboronic acid,;1-t-Butoxycarbonylpiperazinewith acetic acid in tetrahydrofuran;methanol at 20; for 1.5 h;
Stage #2: with sodium tris(acetoxy)borohydride in tetrahydrofuran;methanol at 60;

Steps:

28.1

The N-Boc piperazine (5g, 26.8mmol) and 4-formyl phenylboronic acid (2.68g, 17.9mmol) was dissolved in 15ml four Tetrahydrofuran and 15ml of methanol was added acetic acid (6ml, 43.44mmol), The reaction was stirred for 1.5 hours at room temperature, was added sodium triacetoxy borohydride (9.49g, 44.7mmol), was heated to 60 ° C until the reaction was stirred for completion of the reaction monitored by TLC starting material, Concentrated under reduced pressure was purified by silica gel column chromatography the residue obtained: 4-benzyl - piperazine-1-carboxylate - 4.98g boric acid, White solid), yield: 87.4%, MS m / z (ESI): 321 [M + 1], was used directly in the next reaction.

References:

CN103087077,2016,B Location in patent:Paragraph 0327-0329