Phosphoric Acid → HCID 66665085, compound

Participants

Reaction Steps

To a solution of cyclopentyl methanol (22.3 g, 0.22 mol) and triethylamine (33.8 g, 0.33 mol) in tetrahydrofuran was added dropwise methanesulfonyl chloride (29.3 g, 0.26 mol) with keeping the temperature below 15° C. over 50 minutes, and the reaction mixture was stirred at the same condition for 1 hour. To the mixture was added dropwise water (134 g) with keeping the internal temperature below 15° C. over 10 minutes. To the resultant was further added toluene (232 g), and the mixture was extracted. The organic layer was washed with water (134 g), and the solvent was evaporated under reduced pressure to give a crude product of Compound (Ie) (40.0 g), which was used in the next step without further purification. The resulting Compound (Ie) and hydrazine monohydrate (66.9 g, 1.34 mol) were dissolved in ethanol (178 g), and the reaction mixture was stirred at 60° C. to 65° C. (internal temperature) for 7 hours. The mixture was cooled to room temperature, and partitioned between chloroform (674 g) and water (71.5 g). The chloroform layer was washed with water (71.5 mL, ×2) to give a solution of a free base of Compound (IIff) in chloroform (808 g). To the solution (202 g, equivalent to 55 mmol) were added at room temperature 85% phosphoric acid (6.42 g, 60 mmol) and then 2-propanol (30 g), and the solvent was evaporated under reduced pressure. To the concentrated residue was added 2-propanol (36.7 g), and the solvent was evaporated under reduced pressure (×4). To the concentrated residue (24 g) was added 2-propanol to adjust the total weight to 45 g, and the mixture was stirred at 40° C. for 1 hour. The mixture was cooled to 5° C. over 1.5 hours, and then stirred at 5° C. for 1 hour. The precipitate was collected by filtration, washed with a mixed solution of 2-propanol (1.98 g) and n-hexane (3.47 g), and dried under reduced pressure to give Compound (IIff) (9.33 g, 80%) as a white crystalline solid.

Provenance & Evidence