Lithium hydroxide, monohydrate → Lithium 1-methylsulfonylcyclobutanecarboxylate

Temperature

100 °C

To a solution of methyl 1-methylsulfonylcyclobutanecarboxlate (0.10 g, 0.52 mmol) in 2 mL of dioxane and 2 mL of water was added lithium hydroxide monohydrate (44 mg, 1.0 mmol). After stirring at 100° C. for 1 h, the reaction mixture was concentrated to dryness, and the residue was azeotroped with toluene to give the crude lithium 1-methylsulfonylcyclobutanecarboxylate, which was used without further purification. Thus, the crude lithium salt was suspended in 2 mL of anhydrous dimethylformamide, and was added N-(2S,3S)-[3-(4-chlorophenyl)-2-(3-cyanophenyl)-1-methylpropyl]-amine hydrochloride (0.15 g, 0.52 mmol), tris(pyrrolindinyl)phosphonium hexafluorophosphate (0.41 g, 0.78 mmol) and N-methylmorpholine (0.23 mL, 2.1 mmol). After stirring at room temperature overnight, the reaction mixture was partitioned between water (20 mL) and ether (20 mL). The organic layer was separated, and the aqueous layer was extracted with ether (20 mL). The combined extracts were dried over anhydrous magnesium sulfate, filtered and concentrated to dryness, and the residue was purified by flash chromatography on silica gel eluting with 20 to 40% ethyl acetate in hexane to give the title compound. 1H NMR (500 MHz, CD3OD): δ 7.57 (m, 1H), 7.49 (s, 1H), 7.43 (m, 2H), 7.10 (d, 2H), 6.92 (d, 2H), 4.38 (m, 1H), 3.35-2.63 (m, 7H), 2.93 (s, 3H), 2.14 (m, 1H), 1.98 (m, 1H), 0.98 (d, 3H). LC-MS: m/e 445 (M+H)+ (3.5 min).

1. concentrationthe reaction mixture was concentrated to dryness
2. customthe residue was azeotroped with toluene

ORD record

ord-8975ab6b6f71431ab46e0ebc578ac74d

Source dataset

uspto-grants-2008_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07423067B2