反应 #1477518
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openreactiondata ↗doi:10.6084/m9.figshare.5104873.v1; patent:US05965548
反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.
实验步骤: Dissolve 16-dehydropregnenolone (5.00 g, 15.90 mmol) and 5,5-dibromobarbituric acid (4.55 g, 15.90 mmol) in tetrahydrofuran (60 mL). Add concentrated aqueous hydrogen bromide (100 μL of a 48% solution) to the stirring solution and heat the reaction at reflux for 1 hour. Cool slightly and then concentrate under vacuum to produce a brown oily foam. Dissolve the residue in methylene chloride (350 mL), rinse with 50% saturated sodium bicarbonate (2×200 mL, brine (125 mL), dry over anhydrous magnesium sulfate, filter and concentrate under vacuum to provide 21-bromo-3β-hydroxypregna-5,16-dien-20-one (6.53 g) as an orange-brown solid, slightly contaminated with starting material. heat the reaction at reflux for 1 hour Cool slightly concentrate under vacuum to produce a brown oily foam rinse with 50% saturated sodium bicarbonate (2×200 mL, brine (125 mL) dry over anhydrous magnesium sulfate filter concentrate under vacuum
来源 ID: ord-a3e879b19e2f4560bb0ecf927709924c