Diisopropylamine → 4-(4-But-2-ynyloxybenzenesulfonyl)-piperidine-1,4-dicarboxylic Acid tert-butyl Ester Methyl Ester

Participants

Reaction Conditions

Reaction Steps

To a solution of diisopropylamine (1.58 mL, 11.3 mmol) in THF (25 mL) at 0° C. was added 2.5M n-BuLi(4.68 mL, 11.7 mmol) and the resulting mixture was stirred for 15 min at that temperature. The reaction mixture was cooled to −78° C. and a solution of 1-(tert-butyl)-4-methyl 1,4-piperidinecarboxylate (prepared from example 30, step 1) (2.67 g, 11.0 mmol) in THF (40 mL) was added. The resulting mixture was stirred for 1 h and a solution of 4-but-2-ynyloxy benzenesulfonyl fluoride (2.5 g, 11.0 mmol) in THF (25 mL) was added into it. After stirring for 4 h at rt, the reaction was quenched with satd. aqueous NH4Cl solution and extracted with EtOAc, dried over anhydrous Na2SO4. The crude product was purified by silica gel chromatography to obtain 2.6 g(53%) of the product as a solid; 1H NMR(300 MHz, CDCl3) δ1.44(s, 9H), 1.87(m, 3H), 1.98(m, 2H), 2.32(m, 2H), 2.62(m, 2H), 3.74(s, 3H), 4.17(m, 2H), 4.74(m, 2H), 7.09(d, 2H, J=7.2 Hz), 7.71(d, 2H, J=7.2 Hz).

Provenance & Evidence