Water → HCID 24969673, compound

Participants

Reaction Conditions

Reaction Steps

Phosphorus pentoxide (13.1 kg) was dissolved in methanesulfonic acid (131 liter) warmed, the solution was added to the compound (26.27 kg) obtained in Example 2 (1) above and the mixture was stirred at 65-75° C. for about 3 hours. To the reaction mixture, was added water (342 liter) dropwise while keeping the temperature at 10-50° C., and then the solution was cooled at below 10° C. The precipitated crystalline was collected by filtration and washed with water (393 liter). When the pH of the washing was acidic, the precipitate was washed again. The wet crystalline was dissolved in ethyl acetate (26.3 liter) and n-heptane (105 liter) at 60-70° C., and n-heptane (158 liter) was further added at the same temperature. The solution was stirred at 45-50 for about 3 hours, cooled to below 10° C., and the precipitated crystalline was filtered and washed with ethyl acetate/n-heptane=1/10 (26.3 liter). The wet product was dried under reduced pressure at below 50° C. to give the titled compound (11.5 kg, yield 47%). MS (APCI) m/z: 244 [M+H]+.

Provenance & Evidence