Methanesulfonic Acid → HCID 88920154, compound

Participants

Reaction Conditions

Reaction Steps

A solution of (1S,2R)-PNE (18.7%-w/w, 19.7 g, 18.0 mmol) in THF/toluene (9:1-w/w) was charged to a vessel at room temperature. A solution of diethylzinc in toluene (29.9%-w/w, 6.10 g, 14.8 mmol) was added at 17 to 25° C. and the mixture was aged at said temperature for 30 min, 1-hexyne (97%-w/w, 6.10 g, 72.0 mmol, compound of formula III, wherein R2 is n-butyl) was added at 18° C. and the resulting solution was aged at 20° C. for 60 min. A solution of BuLi in toluene (3.09 mol/kg, 17.8 g, 55.0 mmol) and a solution of 1-(2-amino-5-chlorophenyl)-2,2,2-trifluoroethanone (CN23315, a compound of formula IV, wherein R1 is trifluoromethyl, R8 is 5-chloro, R9 is hydrogen and R10 is hydrogen) in toluene/THF (1:1 w/w) (39.6%-w/w, 33.8 g, 60.0 mmol) were added in parallel to the reaction mixture at 20° C. within 3 h. The addition of BuLi was started 10 min in advance of the CN23315 addition. After completed addition of CN23315 the reaction mixture was stirred for 30 min at 20° C., then heated to 30° C. over a period of 60 min and aged for 6 h at 30° C. The reaction mixture was stirred at 0° C. overnight. HPLC (Method B) indicated 89.6% conversion. The reaction mixture was diluted with toluene (25.8 g) and quenched by addition of aqueous citric acid solution (1 M, 44.1 g). After stirring for 15 min the phases were separated and the organic phase successively washed with water (9.1 g), aqueous NaHCO3 solution (5%-w/w, 24.0 g) and water (12.0 g). The organic phase was partially concentrated (51 g residual solution), diluted with toluene (30 g), and partially concentrated again (58 g residue). The residue was diluted with toluene (59 g) and isopropyl alcohol (1.50 g). Methanesulfonic acid (10.48 g, 114 mmol) was added at 30° C. over a period of 30 min and the mixture was stirred for 30 min. A second portion methanesulfonic acid (2.89 g, 30 mmol) was added at 30° C. over a period of 30 min. The mixture was stirred at 30° C. for 30 min, cooled to 5° C. over a period of 60 min, and aged at 5° C. for 30 min. The crystals were filtered, washed with cold toluene (10 g) and dried under vacuum at 40° C. The crude product (19.3 g) was obtained as yellowish solid with a purity of 93.3% and 99.6% ep according to method B. The product was further purified by slurring it in a mixture of toluene (100 mL) and isopropyl alcohol (2 mL) at room temperature for 3 h. The product (MSA salt of (R)-CN47583, compound of formula II, wherein R1 is trifluoromethyl, R2 is n-butyl, R8 is 5-chloro, R9 is hydrogen and R10 is hydrogen) was filtered, washed with toluene (10 mL) and dried at 40° C. under vacuum. The product was obtained as white solid (17.1 g, 35.3 mmol, 59% yield) with a purity of 93.3% and 99.9% ep according to method B, and an assay of 92.8% w-/w according to 1H-NMR.

Provenance & Evidence