Diisopropylethylamine → tert-butyl 4-(4-chloro-3-fluorophenyl)-4-(1-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazine-4-carbonyl)piperidine-1-carboxylate

Participants

Reaction Steps

(5R,7R)-5-methyl-4-(piperazin-1-yl)-6,7-dihydro-5H-cyclopenta[d]pyrimidin-7-ol dihydrochloride (35.0 mg, 0.114 mmol) and 1-(tert-butoxycarbonyl)-4-(4-chloro-3-fluorophenyl)piperidine-4-carboxylic acid (40.8 mg, 0.114 mmol) were dissolved in DCM (1.1 mL) and treated with DIEA (0.0595 ml, 0.342 mmol) at ambient temperature. The mixture was allowed to homogenize before the HBTU (47.5 mg, 0.125 mmol) was added in one lot. The reaction was allowed to stir for four hours to completion by LCMS analysis of the crude. The reaction was diluted with DCM, washed with diluted NaHCO3 solution, washed with water, washed with brine, and separated. The organic layer was dried over Na2SO4, filtered, and concentrated in vacuo. The residue was purified by chromatography (silica gel eluted with 5% methanol in ethyl acetate) to afford the pure tert-butyl 4-(4-chloro-3-fluorophenyl)-4-(1-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazine-4-carbonyl)piperidine-1-carboxylate (15.0 mg, 22.9% yield) as a pale yellow oil. MS (APCI+) [M+H] +574; Rf: 2.92.

Provenance & Evidence