Oxalyl chloride → Methyl 1-(4-oxochroman-6-yl)cyclopropanecarboxylate
Reaction equation
[CH3:1][O:2][C:3]([C:5]1([C:8]2[CH:13]=[CH:12][C:11]([O:14][CH2:15][CH2:16][C:17]([OH:19])=O)=[CH:10][CH:9]=2)[CH2:7][CH2:6]1)=[O:4].C(Cl)(=O)C(Cl)=O>C(Cl)Cl.CN(C=O)C>[O:19]=[C:17]1[C:10]2[C:11](=[CH:12][CH:13]=[C:8]([C:5]3([C:3]([OH:2])=[O:4])[CH2:6][CH2:7]3)[CH:9]=2)[O:14][CH2:15][CH2:16]1.[O:19]=[C:17]1[C:10]2[C:11](=[CH:12][CH:13]=[C:8]([C:5]3([C:3]([O:2][CH3:1])=[O:4])[CH2:6][CH2:7]3)[CH:9]=2)[O:14][CH2:15][CH2:16]1Participants
Reactant 2
Product 2
Reagents, catalysts & solvents 2
Procedure
To a solution of 1-[4-(2-carboxy-ethoxy)-phenyl]-cyclopropanecarboxylic methyl ester (5.0 g, 20 mmol) in CH2Cl2 (50 mL) were added oxalyl chloride (4.8 g, 38 mmol) and two drops of DMF at 0° C. The mixture was stirred at 0˜5° C. for 1 h and then evaporated under vacuum. To the resulting mixture was added CH2Cl2 (50 mL) at 0° C. and stirring was continued at 0˜5° C. for 1 h. The reaction was slowly quenched with water and was extracted with EtOAc (50 mL×3). The combined organic extracts were dried over anhydrous Na2SO4 and evaporated under vacuum to give the crude product, which was purified by column chromatography on silica gel (petroleum ether/ethyl acetate 20:1-2:1) to give 1-(4-oxochroman-6-yl)cyclopropanecarboxylic acid (830 mg, 19%) and methyl 1-(4-oxochroman-6-yl)cyclopropanecarboxylate (1.8 g, 38%). 1-(4-Oxochroman-6-yl)cyclopropane-carboxylic acid:
Workup
- customevaporated under vacuum
- additionTo the resulting mixture was added CH2Cl2 (50 mL) at 0° C.
- stirringstirring
- waitwas continued at 0˜5° C. for 1 h
- customThe reaction was slowly quenched with water
- extractionwas extracted with EtOAc (50 mL×3)
- dry with materialThe combined organic extracts were dried over anhydrous Na2SO4
- customevaporated under vacuum
- customto give the crude product, which
- customwas purified by column chromatography on silica gel (petroleum ether/ethyl acetate 20:1-2:1)
Sources & evidence
- ORD record
- ord-f495753dc31b4e27bf0982da89c2c295
- Source dataset
- uspto-grants-2010_01
- Patent number
- US07645789B2
Reaction notes
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