1-Pentynylbenzene → 5-Phenyl-4-propylisoxazole-3-carboxylic acid
Reaction equation
[C:1]([C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1)#[C:2][CH2:3][CH2:4][CH3:5].[N+:12]([CH:15](C(OCC)=O)[C:16]([O:18]CC)=[O:17])([O-])=[O:13]>C(OCC)(=O)C>[C:6]1([C:1]2[O:13][N:12]=[C:15]([C:16]([OH:18])=[O:17])[C:2]=2[CH2:3][CH2:4][CH3:5])[CH:7]=[CH:8][CH:9]=[CH:10][CH:11]=1Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 160 °C
Procedure
Pent-1-ynylbenzene (17 mL, 106 mmol) and diethyl 2-nitromalonate (30 mL, 172 mmol) were placed in a stainless steel pressure bomb and heated to 160° C. for 18 hours. Cooled in ice bath then slowly released remaining pressure. The reaction mixture was diluted with ethyl acetate and washed with 1N NaOH. The aqueous layer was back extracted once. The organic layer was dried over MgSO4, filtered, and concentrated. The crude material was treated with 1N NaOH/EtOH at 75° C. for two hours. Diluted with water and washed with EtOAc. The aqueous layer was separated, acidified with concentrated HCl, and extracted with EtOAc. The organic layer was dried with MgSO4, filtered and concentrated to afford 20 g of 5-phenyl-4-propylisoxazole-3-carboxylic acid.
Workup
- temperatureCooled in ice bath
- washwashed with 1N NaOH
- extractionThe aqueous layer was back extracted once
- dry with materialThe organic layer was dried over MgSO4
- filtrationfiltered
- concentrationconcentrated
- additionThe crude material was treated with 1N NaOH/EtOH at 75° C. for two hours
- additionDiluted with water
- washwashed with EtOAc
- customThe aqueous layer was separated
- extractionextracted with EtOAc
- dry with materialThe organic layer was dried with MgSO4
- filtrationfiltered
- concentrationconcentrated
Sources & evidence
- ORD record
- ord-0bef77cea6204b01a13c822a6f83aa29
- Source dataset
- uspto-grants-2013_03
- Patent number
- US08399451B2
Reaction notes
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