Propargyl bromide → N-(Prop-2-ynyloxy)phthalimide
Reaction equation
[OH:1][N:2]1[C:6](=[O:7])[C:5]2=[CH:8][CH:9]=[CH:10][CH:11]=[C:4]2[C:3]1=[O:12].[CH2:13](Br)[C:14]#[CH:15].C(N(CC)CC)C>CN(C=O)C>[CH2:15]([O:1][N:2]1[C:3](=[O:12])[C:4]2[C:5](=[CH:8][CH:9]=[CH:10][CH:11]=2)[C:6]1=[O:7])[C:14]#[CH:13]Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Procedure
To a stirred solution of N-hydroxyphthalimide (50.5 g) and propargyl bromide (37.0 g) in DMF (250 ml) at 0° C. was added drop-wise triethylamine (50 ml). The cooling bath was removed and the reaction mixture was stirred at room temperature for 4 hours. The mixture was poured into water containing some ice and the precipitated material was isolated by filtration. The crude product was recrystallised from ethanol and gave 2-prop-2-ynyloxy-isoindole-1,3-dione (47.5 g). Step 2: The above obtained phthalimide intermediate (1 mmol) was mixed with p-tolyl isocyanate (2.8 mmol), triethylamine (0.05 mmol) and 1-nitrobutane (1.44 mmol) in toluene (3 ml). The reaction mixture was stirred at room temperature for 48 hours, filtrated and subjected to column chromatography on silica, affording 2-(3-propyl-isoxazol-5-ylmethoxy)-isoindole-1,3-dione. Step 3: The above cycloaddition product was dissolved in methanol+dichloromethane and hydrazine monohydrate (1 eq.) was added. The reaction mixture was stirred at room temperature for 20 hours and placed at 5° C. for 3 hours. The solid material was removed by filtration and the filtrate was evaporated under reduced pressure and gave the title compound. 13C-NMR (DMSO-d6) δ 169.0, 163.2, 103.0, 67.4, 27.2, 21.0, 13.5.
Workup
- customThe cooling bath was removed
- additionThe mixture was poured into water containing some ice
- customthe precipitated material was isolated by filtration
- customThe crude product was recrystallised from ethanol
Sources & evidence
- ORD record
- ord-aa6d05cae15c4979a5f779a07e43c4ed
- Source dataset
- uspto-grants-2011_10
- Patent number
- US08034811B2
Reaction notes
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