7-Bromo-4-chromanone

A solution of diisobutylaluminum hydride in heptane (1.0 M, 60 mL, 60.0 mmol) was added dropwise to a solution of 7-bromo-4H-chromen-4-one (4.5 g, 20.0 mmol) in tetrahydrofuran at -78 °C under an atmosphere of argon over a period of 30 minutes. After 30 minutes the reaction was quenched with a mixture of silica gel (10 g), and water (10 mL). The mixture was allowed to warm to room temperature and was filter through celite and the tetrahydrofuran was removed under reduced pressure. The residue was taken up in chloroform (100 mL) and washed with sodium hydroxide (IN, 25 mL) and dried over sodium sulfate. The mixture was filtered and the solvent was removed under reduced pressure. The residue was subjected to flash chromatography with eluant of dichloromethane. The product containing fractions were combined and the solvent was removed under reduced pressure to provide 7- bromochroman-4-one (3.57 g, 15.7 mmol, 78 percent).Intermediate 5; 7-Bromo-2, 3-dhydro-4W-chromen-4-one.;The solution of 7-Bromo-4H-chromen-4-one (26.0 g, 116 mmol) in absolute THF (500 mL) was stirred under argon for 1 h and then it was cooled to -80 A solution of XXV-3 (2.9 g, 12.9 mmol) in THF (10 mL) was cooled to −78° C., DIBAl-H (24 mL, 24 mmol) was added and the resulting solution was stirred at −78° C. for 30 min., Then sat.NH7-Bromo-4-chromanone. Weighed compound 7 (5g), added to a three-necked bottle, and weighed 50mL of polyphosphoric acid into a 100mL three-necked bottle.The reaction system was heated in an oil bath and stirred at 80 ° C for 2 hours. Lower the system temperature to room temperature, The reaction was quenched by adding 100 mL of water and stirring for 10 minutes, and extracted three times with 100 mL of ethyl acetate.The organic phases are combined, then the organic phase is washed with water and the organic phase washed with saturated sodium chloride.Dried over anhydrous sodium sulfate, filtered and concentrated, the crude product was purified by column chromatography (mobile phase:Ethyl acetate: petroleum ether = 1:3) was purified. 3.1 g (60percent) of a yellow solid were obtained.Example 79B; The product from Example 79A (7.935 g, 32.3 mmol) was refluxed in ethylene glycol for 4 h. The solution was then cooled to rt and poured into water. The mixture was extracted with ether, then the extracts were washed with water and brine. Concentration in vacuo, followed by silica gel chromatography (9:1 hexane-ethyl acetate to 65:35 hexane-ethyl acetate, eluent gradient), afforded Example 79B as a thick yellow oil, 979 mg (13percent).

Molecular Weight:227.05
XLogP3:2.1
Hydrogen Bond Acceptor Count:2
Exact Mass:225.96294
Monoisotopic Mass:225.96294
Topological Polar Surface Area:26.3
Heavy Atom Count:12
Complexity:193
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes