[NH2:1][C:2]1[N:7]2[N:8]=[C:9]([CH3:11])[CH:10]=[C:6]2[N:5]=[CH:4][C:3]=1[C:12](OC)=[O:13].CCOC(C)=O.O>C1COCC1>[NH2:1][C:2]1[N:7]2[N:8]=[C:9]([CH3:11])[CH:10]=[C:6]2[N:5]=[CH:4][C:3]=1[CH2:12][OH:13]To a 1 L three-necked round bottom flask was added Methyl 7-amino-2-methylpyrazolo[1,5-a]pyrimidine-6-carboxylate (20.6 g, 100 mmol, 1.0 eq.) and THF (400 mL). The mixture was cooled to 0° C. and LiBHEt3 (315 mL of a 1.0 M solution in THF, 315 mmol, 3.0 eq.) was added slowly through an addition funnel under nitrogen. After addition, the mixture was stirred at room temperature for 4 h. Additional LiBHEt3 (30 mL of a 1.0 M solution in THF, 30 mmol, 0.3 eq.) was added and the mixture was stirred for an additional 1 h. The mixture was slowly treated with EtOAc (600 mL) and then water (300 mL). The layers were separated and the aqueous phase was extracted with EtOAc (2×300 mL). The combined organic phases were dried over anhydrous Na2SO4. After filtration and concentration, the residue was purified by a short silica gel column (2.5 inch in height and 4 inch in diameter) using MeOH in CH2Cl2 as the eluent. Concentration by rotary evaporation provided (7-amino-2-methylpyrazolo[1,5-a]pyrimidin-6-yl)methanol (1-1) as a light yellowish solid.
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