反应 #1396199
相关文献 (1)
openreactiondata ↗doi:10.6084/m9.figshare.5104873.v1; patent:US08030495B2
反应条件: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.
实验步骤: To a vigorously stirred solution diethyl ether (215 mL) in 40% KOH (160 mL) in a plastic bottle at 0° C. was added 1-methyl-3-nitrosoguanidine (15.5 g, 105 mmol) over a period of 5 minutes and stirred for 0.5 h at 0° C. The mixture was then transferred to a plastic separatory funnel from which the aqueous phase was separated from the organic phase. The organic phase was then added very slowly over a period of 0.5 h to a plastic bottle containing a solution of 7-7 (6.4 g, 32.5 mmol) in diethyl ether (130 mL) at 0° C. and stirred overnight. The system was then bubbled through with nitrogen for 0.5 h and the reaction contents were poured in to a round bottom flask and the contents were concentrated in vacuo to yield a yellow solid. To a solution of this yellow solid (1.0 g, 4.19 mmol) in DMF (8 mL) at 25° C. was added cesium carbonate (2.04 g, 6.28 mmol) and iodomethane (0.314 mL, 5.0 mmol) and the system was stirred overnight. The mixture was diluted with EtOAc and washed with water. The combined organic layers were dried over MgSO4 and concentrated to a gold oil. To this gold oil (1.0 g, 3.96 mmol) in DCM (8 mL) at 25° C. was added lead tetraacetate (2.63 g, 5.94 mmol) and the system was stirred for 2 h. The system was cooled to 0° C. and any excess lead tetraacetate was destroyed with a drop of acetic acid and 3 drops of hydrazine hydrate. The mixture was then dried over potassium carbonate, concentrated and purified by normal phase silica gel chromatography (0 to 100% EtOAc in hexanes) to afford a white solid. To a solution of this white solid (0.466 g, 1.85 mmol) in THF (2.0 mL) and MeOH (2.0 mL) at 25° C. was added a 1M solution of KOH (2.79 mL, 2.79 mmol) and the system was stirred overnight. The mixture was then neutralized with 1N HCl to a pH of 5. Solvent was then removed in vacuo and the residue was azeotroped 2× with toluene to afford the title compound as a yellow powder. ESI+ MS: [M+H]÷ 237.2. The mixture was then transferred to a plastic separatory funnel from which the aqueous phase was separated from the organic phase The organic phase was then added very slowly over a period of 0.5 h to a plastic bottle stirred overnight The system was then bubbled through with nitrogen for 0.5 h the reaction contents were poured in to a round bottom flask the contents were concentrated in vacuo to yield a yellow solid the system was stirred overnight washed with water The combined organic layers were dried over MgSO4 concentrated to a gold oil the system was stirred for 2 h The system was cooled to 0° C. any excess lead tetraacetate was destroyed with a drop of acetic acid and 3 drops of hydrazine hydrate The mixture was then dried over potassium carbonate concentrated purified by normal phase silica gel chromatography (0 to 100% EtOAc in hexanes) to afford a white solid the system was stirred overnight Solvent was then removed in vacuo the residue was azeotroped 2× with toluene
来源 ID: ord-04d4d2fe0a8749328209e48ac6d8a70c