2,5-Dibromopyrimidine

Off-White crystal

Preparation of relevant pyri(mi)dyl halides A-H. Key: (a) NBS, NH[00159] Scheme 1. Preparation of relevant pyri(mi)dyl halides A-H. Key: (a) NBS, NHA mixture of 5-bromo-lH-pyrimidin-2-one (see step (e) above; 1.40 g, 8.0 mmol), POBr3 (2.8 g, 9.8 mmol) and PBr3 (7.7 mL) was refluxed for 1.5 h. After cooling to room temperature the reaction was poured into a mixture of crushed ice and Na(at)C03 (saturated aq. solution) and extracted with EtOAc (3x100 mL). The combined organic extracts were washed with brine, dried with Na2S04 and concentrated. The residue was re-dissolved in EtOAc/light petrol (1: 1) and filtered through a silica pad. Concentration of the filtrate gave the sub-title compound (0.95 g, 50 percent).In a 250 mL round bottom flask, N-Boc-3-iodo-5-methoxyindole 1a (5 g, 13.4 mmol) and tetrakis (triphenylphosphine) palladium (0.53 g, 0.4 mmol) were dissolved in 50 mL 1 , 4-dioxane, replacement gas.Triethylamine (19 mL, 134 mmol) and pinacol borane (3 mL, 20.1 mmol) were added with a syringe, and the mixture was stirred at 80 C after the dropwise addition.Stop heating after 3h, and after cooling to room temperature, add General procedure: In a dry sealed tube under argon were placed, to a solution of 1-Boc-piperazine (5.04 mmol), potassium carbonate (13.1 mmol) in acetonitrile (12.6 mL) was added 2, 5-dibromo pyrimidine13(5.04 mmol). The mixture was allowed to stir at 80 C for 12 h. After completion of the reaction (monitored by TLC), the mixture was then cooled at room temperature, then it was quenched with saturated aqueous NH4Cl (10 mL) and extracted with EtOAc. The organic layers were dried over anhydrous MgSO4and concentrated in vacuo. The resulting residue was purified by flash column chromatography on silica gel (EtOAc:n-hexane = 1:8) to afford piperazine11a.General procedure: In a dry sealed tube under argon were placed, to a solution of 1-Boc-piperazine (5.04 mmol), potassium carbonate (13.1 mmol) in acetonitrile (12.6 mL) was added 2, 5-dibromo pyrimidine13(5.04 mmol). The mixture was allowed to stir at 80 C for 12 h. After completion of the reaction (monitored by TLC), the mixture was then cooled at room temperature, then it was quenched with saturated aqueous NH4Cl (10 mL) and extracted with EtOAc. The organic layers were dried over anhydrous MgSO4and concentrated in vacuo. The resulting residue was purified by flash column chromatography on silica gel (EtOAc:n-hexane = 1:8) to afford piperazine11a.General procedure: In a dry sealed tube under argon were placed, to a solution of 1-Boc-piperazine (5.04 mmol), potassium carbonate (13.1 mmol) in acetonitrile (12.6 mL) was added 2, 5-dibromo pyrimidine13(5.04 mmol). The mixture was allowed to stir at 80 C for 12 h. After completion of the reaction (monitored by TLC), the mixture was then cooled at room temperature, then it was quenched with saturated aqueous NH4Cl (10 mL) and extracted with EtOAc. The organic layers were dried over anhydrous MgSO4and concentrated in vacuo. The resulting residue was purified by flash column chromatography on silica gel (EtOAc:n-hexane = 1:8) to afford piperazine11a. tert-Butyl 4-(5-bromopyrimidin-2-yl)piperazine-1-carboxylate(11a): Yield: 88%;1H-NMR (400 MHz, CDCl3)delta8.30 (s, J= 2.0 Hz, 2H), 3.78-3.75 (t, J= 5.2 Hz, 4H), 3.49-3.47 (t, J= 5.2 Hz, 4H), 1.48 (s, 9H).13C-NMR (100 MHz, CD3OD)delta161.2, 159.2, 156.46, 107.15, 81.5, 44.8, 28.6.

Molecular Weight:237.88
XLogP3:1.9
Hydrogen Bond Acceptor Count:2
Exact Mass:237.85642
Monoisotopic Mass:235.85847
Topological Polar Surface Area:25.8
Heavy Atom Count:8
Complexity:70.4
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes