Nitrogen → [1-(5-Hydroxymethyl-furan-2-ylmethyl)-1H-pyrazol-4-yl]-carbamic acid 2-chloro-benzyl ester

In a flame dried round-bottomed flask equipped with a magnetic stir bar and under inert atmosphere (N2), a solution of 5-[4-(2-chloro-benzyloxycarbonylamino)-pyrazol-1-ylmethyl]-furan-2-carboxylic acid methyl ester (3.30 g, 8.46 mmol) in MeOH (33.0 mL) was treated portionwise, at rt with NaBH4 (3.33 g, 84.60 mmol). The reaction mixture was stirred at rt overnight before being quenched by pouring in sat. aq. NH4Cl (100 mL), extracted with EA (3×100 mL). The combined org. extracts were dried over MgSO4, filtered, and the solvents were removed under reduced pressure. Purification of the residue by FC (30:70 hept-EA) gave the title compound. TLC: rf (30:70 hept-EA)=0.22. LC-MS-conditions 02: tR=0.86 min; [M+H]+=362.32. 1H NMR (400 MHz, CDCl3) δ 2.94 (s, 1H), 4.52 (s, 2H), 5.15 (s, 2H), 5.28 (s, 2H), 6.21 (s, 1H), 6.28 (s, 1H), 7.04 (s, 1H), 7.22-7.35 (m, 2H), 7.35 (s, 1H), 7.35-7.46 (m, 2H), 7.69 (s, 1H).