Sulfuric Acid → 1-[2-(4-Benzyl-4-hydroxy-piperidin-1-yl)-ethyl]-3-(2-methyl-quinolin-4-yl)-urea Sulfate Trihydrate

Participants

Reaction Conditions

Reaction Steps

1-[2-(4-benzyl-4-hydroxy-piperidin-1-yl)-ethyl]-3-(2-methyl-quinolin-4-yl)-urea (15.4 kg, 1 equivalent) is dissolved in ethanol (78 L) and the mixture is heated at 50° C. Aqueous sulfuric acid (1M, 1.1 equivalents) is added during 35 minutes. The crystallization is initiated by a wet seed of Example 1 (1%) as described below. The suspension is cooled to 1° C. with a cooling rate of 14° C./h and maintained at this temperature at least 11 hours before filtration and washing with aqueous ethanol (50% W/W, 50 L). The solid is dried at 30° C. under a wet stream of nitrogen (33-40% RH) to provide the title compound with a purity of 99.4% with a yield of approximately 79%.

Provenance & Evidence