(1R,2S)-2-[(2-methylpropan-2-yl)oxycarbonylamino]cyclopentane-1-carboxylic acid

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of (1R,2S)-2-[(tert-butoxycarbonyl)amino]cyclopentanecarboxylic acid (1.0 g), DMF (10 ml), 3-(aminosulfonyl)propylacetic acid (0.95 ml), CDI(0.85 g), and DBU (0.80 g) was stirred at room temperature for 3 days. To the reaction mixture were added 1 M hydrochloric acid and ethyl acetate, and the organic layer was separated. The organic layer was washed with a saturated sodium bicarbonate solution, then dried over anhydrous magnesium sulfate, and concentrated under reduced pressure to obtain 3-{[({(1R,2S)-2-[(tert-butoxycarbonyl)amino]cyclopentyl}carbonyl)amino]sulfonyl}propylacetic acid (1.2 g). the organic layer was separated The organic layer was washed with a saturated sodium bicarbonate solution dried over anhydrous magnesium sulfate concentrated under reduced pressure

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: N-Cyclopropyl-N-piperidin-4-yl-3-trifluoromethyl-benzenesulfonamide (0.372 g, 1.1 mmol), HOBt (0.145 g, 1.1 mmol), EDCI (0.246 g, 1.32 mmol) and rac-cis-2-(tert-butoxycarbonylamino)-cyclopentanecarboxylic acid (0.275 g, 1.2 mmol) were dissolved in 5 ml of dry CH2Cl2. The mixture allowed to stir at room temperature for 12 hours. The reaction mixture was diluted with 30 ml of CHCl3 and washed with 10 ml of H2O. The organic layer was dried over MgSO4 and concentrated to dryness. The crude product was purified through a column of silica gel with a gradient of 30% to 70% EtOAc in hexane to afford the rac-((1R,2S)-2-{4-[cyclopropyl-(3-trifluoromethyl-benzenesulfonyl)-amino]-piperidine-1-carbonyl}-cyclopentyl)-carbamic acid tert-butyl ester (592 mg, 99%). washed with 10 ml of H2O The organic layer was dried over MgSO4 concentrated to dryness The crude product was purified through a column of silica gel with a gradient of 30% to 70% EtOAc in hexane