反応 #59644

反応方程式

sodium borohydride

acetate

[1-((S)-2-Benzyloxycarbonylamino-propyl)-7-bromo-1H-indazol-6-yloxy]-acetic acid ethyl ester

sodium borohydride

calcium chloride

→

solid

収率 82.0%

{(S)-2-[7-Bromo-6-(2-hydroxy-ethoxy)-indazol-1-yl]-1-methyl-ethyl}-carbamic acid benzyl ester

収率 82.0%

溶媒

tetrahydrofuran

ethanol

反応条件

後処理

1. 1
   workup.STIRRINGThe suspension was stirred at ambient temperature for 1 h
2. 2
   その他The volatiles were evaporated
3. 3
   workup.ADDITIONthe residue mixed with water
4. 4
   抽出extracted with ethyl acetate (3×50 mL)
5. 5
   乾燥The combined extracts were dried over magnesium sulfate
6. 6
   ろ過filtered
7. 7
   その他evaporated to dryness

実験手順

To a solution of the acetate from Step B (0.90 g, 1.84 mmol) in a mixture of tetrahydrofuran (20 mL) and ethanol (20 mL) was added sodium borohydride (70 mg, 1.84 mmol) and calcium chloride (0.21 g, 1.84 mmol) with stirring. The suspension was stirred at ambient temperature for 1 h and more sodium borohydride (70 mg, 1.84 mmol) was added. The reaction was monitored by TLC until no starting material remained. The volatiles were evaporated and the residue mixed with water and extracted with ethyl acetate (3×50 mL). The combined extracts were dried over magnesium sulfate, filtered and evaporated to dryness. Chromatography on silica eluting with a gradient of 20% to 50% EtOAc/hexane gave a solid (0.67 g, 82%): mp 97-99° C.; LCMS (+APCI) 448, 450 (M+H).

出典