Hydrochloric Acid → trans-(4-isopropylpiperazin-1-yl)(2-(1-methyl-1H-pyrazol-4-yl)cyclopropyl)methanone

Participants

Reaction Conditions

Reaction Steps

45A (380 mg, 1.45 mmol) dissolved in 5 mL of anhydrous DMSO was added to a suspension containing (CH3)3S(I)O (3188 mg, 14.48 mmol) prereacted with NaH (579 mg, 14.48 mmol) in 15 mL of anhydrous DMSO. The reaction mixture was heated at 50° C. in an oil bath overnight. The reaction mixture was concentrated under high vacuum to remove as much DMSO as possible, the resulting crude material was then dissolved in EtOAc and washed with a small amount of H2O. The aq. phase was extracted with EtOAc (2×50 ml). The organic phases were combined dried over MgSO4 then filtered on a thin pad of silica gel (1 cm). The silica gel was washed with more EtOAc and the resulting solution was concentrated under reduced pressure then purified on a 40 g silica column on the Companion machine using 0 to 20% MeOH in EtOAc gradient (with two 10 plateau at 10% MeOH then at 20% MeOH). The desired fractions were combined and concentrated under reduced pressure. These fractions were found to still contain some starting material. These samples were combined and repurified on preparative reverse phase chromatography (LCMS) using the long high pH 35-55% gradient on the XBridge Prep C18 OBD, 30×150, 5 um column. The pure fractions were combined and concentrated under reduced pressure. The resulting residue was placed under high vacuum overnight. The yellow liquid was dissolved in 1 ml of distilled H2O and 300 μL of HCl 2N was added to the solution which was then filtered and freeze dried to yield 46.4 mg 45B (9% yield) as a yellow solid HCl salt. 1H NMR (400 MHz, METHANOL-d4) δ ppm 1.46-1.60 (m, 1H) 2.28-2.48 (m, 2H) 2.99-3.30 (m, 4H) 3.52-3.64 (m, 3H) 4.04 (s, 3H) 4.54-4.78 (m, 2H) 8.01 (s, 1H) 8.03 (s, 1H). ES[M+H]+=277.2, HRMS[M+H]+ calc. for C15H24N4O+H=277.20229, [M+H]+ obs.=277.20211.

Provenance & Evidence