[Br:1][C:2]1[N:7]=[C:6]([NH2:8])[CH:5]=[CH:4][CH:3]=1.[H-].[Na+].CS(O[CH2:16][CH:17]1[CH2:22][O:21][C:20]([CH3:24])([CH3:23])[CH2:19][O:18]1)(=O)=O.NC1C=CC=CN=1>CN(C=O)C.CCOC(C)=O>[Br:1][C:2]1[N:7]=[C:6]([NH:8][CH2:16][CH:17]2[CH2:22][O:21][C:20]([CH3:24])([CH3:23])[CH2:19][O:18]2)[CH:5]=[CH:4][CH:3]=1
6-Bromopyridin-2-amine (771 mg, 4.46 mmol) was dissolved in 10 mL of anhydrous DMF and cooled to 0° C. NaH (60% in mineral oil, 214 mg, 5.35 mmol) was added. After 10 min the solution was warmed to ambient temperature and stirred for 15 min until bubbling ceased, to give a dark green solution. (5,5-Dimethyl-1,4-dioxan-2-yl)methyl methanesulfonate (500 mg, 2.23 mmol) in 2 mL of DMF was added. After the addition was completed the solution was stirred at ambient temperature for 20 min, then heated at 60° C. for 1.5 hr. It was diluted with EtOAc and washed four times with water. The aqueous layers were combined and extracted once with EtOAc. The organic layers were combined, dried over Na2SO4 and concentrated. The resulting residue was purified on a silica gel column (heptane:EtOAc 1:0 to 1:1) to give the product contaminated with the starting aminopyridine. Another purification on silica gel column (DCM:ether 20:1) gave the pure product (306 mg, 46%). LC-MS (m/z): 301.0/303.0 (M+H), retention time=0.89 min.
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