Sodium borohydride → HCID 136018754, compound

Participants

Reaction Steps

A mixture of Example 84 Part B (1.8575 g, 4.60 mmol) and NiBr2(DME) (142 mg, 0.46 mmol) in DMPU (100 mL) was treated with NaBH4 (697 mg, 18.4 mmol) under stirring at room temperature. After 20 h, there was still significant amount of starting material left, therefore more NaBH4 (500 mg, 13.2 mmol) and NiBr2(DME) (1.44 g, 4.67 mmol) were added. Over the subsequent 24 h, additional NaBH4 (2.0 g, 53 mmol) and NiBr2(DME) (2.7 g, 8.75 mmol) were added to push the reaction to completion. The mixture was then quenched carefully with MeOH at ice temperature and filtered. The filtrate was neutralized with 1.0 N HCl to PH=7.0, precipitating some sticky solid. The solution layer was separated and concentrated. The residual solution was precipitated with EtOAc/hexanes to remove DMPU. The precipitated solid was purified by flash chromatography (MeOH/CHCl3, 3%), giving the title compound (658 mg, 44% yield). ESI m/z=326.25 [(M+H)+; calcd for C16H15N5O3+H: 326.13].

Provenance & Evidence