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 hand a solution of 4-but-2-ynyloxy benzenesulfonyl fluoride (2.5 g, 11.0 mmol) in THF (25 mL) was added into it. After sting 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, 2), 4.74 (m, 2H), 7.09 (d, 2H, J=7.2 Hz), 7.71 (d, 2H, J=7.2 Hz).

Provenance & Evidence