p-Toluenesulfonic acid monohydrate → N-(4-bromo-2-methoxy-5-nitrophenyl)-4-(4,5,6,7-tetrahydropyrazolo[1,5-a]pyridin-3-yl)pyrimidin-2-amine

Participants

Reaction Steps

A solution of 3-(2-chloropyrimidin-4-yl)-4,5,6,7-tetrahydropyrazolo[1,5-a]pyridine (Intermediate 128, 0.893 g, 3.80 mmol), p-toluene sulphonic acid monohydrate (1.034 g, 5.43 mmol) and 4-bromo-2-methoxy-5-nitroaniline (Intermediate 4, 0.895 g, 3.62 mmol) in 2-pentanol (35 mL) was heated at reflux for 16 h under an atmosphere of N2. The mixture was then allowed to cool, and was concentrated in vacuo. The resulting residue was triturated in CH3CN until a yellow precipitate formed. The solid was collected by filtration and was washed with diethyl ether. The solid then was dissolved in 10% CH3OH in CH2Cl2 and the resulting solution was washed twice with sat. NaHCO3, then with water. The solution was then dried (MgSO4) and concentrated in vacuo. The resulting residue was triturated with CH3CN, the resulting solid collected by filtration, washed with diethyl ether, and then air dried to give the title compound (0.946 g, 59%) as a yellow solid; 1H NMR: 1.80-1.87 (2H, m), 1.96-2.03 (2H, m), 3.11 (2H, t), 4.04 (3H, s), 4.13 (2H, t), 7.17 (1H, d), 7.50 (1H, s), 8.13 (1H, s), 8.21 (1H, s), 8.45 (1H, d), 9.10 (1H, s); m/z: ES+ MH+ 445/447.

Provenance & Evidence