Benzene → HCID 73457211, compound

Participants

Reaction Steps

To methyl 2-chloro-3-formyl-4-methoxybenzoate in an amount of 3.08 g (0.0135 mole), were added 30 ml benzene and then 2-oxopropylidenetriphenylphosphorane in an amount of 4.52 g (0.0142 mole), and the resulting mixture was then stirred for an hour under reflux and heating. After cooling the reacted-mixture, insoluble materials therein were separated by filtration, and methyl 2-chloro-3-(3-oxo-1-butenyl)-4-methoxybenzoate obtained by condensing the solvent in the mixture under reduced pressure was dissolved in a mixed-solvent of 25 ml ethanol and 25 ml pyridine, and the resulting solution was stirred for an hour under reflux and heating following to the addition of hydroxylamine hydrochloride in an amount of 3.3 g (0.047 mole) into the solution. The reacted-mixture was poured into ice water and extracted with ethyl acetate, and the ethyl acetate layer obtained was washed with 1N-hydrochloric acid and saturated saline solution, respectively, and dried with anhydrous magnesium sulfate. The solvent remained in the layer was distillated out under reduced pressure to obtain methyl 2-chloro-3-(3-hydroxyimino-1-butenyl)-4-methoxybenzoate. The obtained product was then dissolved in 50 ml THF, whereto 40 ml aqueous solution of sodium hydrogenbicarbonate in an amount of 4.1 g (0.049 mole) was added, and the resulting mixture was then further added with both 35 ml aqueous solution of potassium iodide in an amount of 7.4 g (0.045 mole) and iodine in an amount of 3.4 g (0.014 mole) and then stirred for 3 hours under reflux and heating while blocking light. The reacted-mixture was poured into ice water and extracted with ethyl acetate following to the addition of sodium hydrogensulfite into the mixture. The organic layer obtained was washed with saturated saline solution and dried with anhydrous magnesium sulfate, then solvent remained in the layer was distillated out under reduced pressure. The residue obtained was purified by using a silica gel column chromatography to obtain methyl 2-chloro-4-methoxy-3-(3-methyl-1,2-isoxazol-5-yl)benzoate in an amount of 2.2 g. The yield was 53.5%.

Provenance & Evidence