1-Pentynylbenzene → 5-Phenyl-4-propylisoxazole-3-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

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.

Provenance & Evidence