The following are listed as examples of compounds of the formula III: ... 3-phenyl-6-methyl-benzomorpholine, 7-methyl-benzomorpholine, 6-methyl-benzomorpholine, 8-methyl-benzomorpholine, 6-chloro-benzomorpholine, 6-methoxy-benzomorpholine, 7-chloro-benzomorpholine, 7-methoxy-benzomorpholine, 6,8-dimethyl-benzomorpholine, 6,7-dimethyl-benzomorpholine, 3-methyl-benzomorpholine, 3-ethyl-benzomorpholine, 3-ethyl-6-methyl-benzomorpholine, 3-propyl-benzomorpholine, 3-[p-methyl]-phenyl-benzomorpholine, 3-[p-chloro]-phenyl-7-methyl-benzomorpholine, ...
[ 944356-53-0 ]
[ 26367-48-6 ]
(E)-4-(6,8-dimethyl-2,3-dihydrobenzo[1,4]oxazin-4-yl)-4-oxo-2-butenoic acid ethyl ester[ No CAS ]
Operation in experiment
With pyridine In ethyl acetate at 1 - 40℃; for 120h;
step 2 Production of (E)-4-(6,8-dimethyl-2,3-dihydrobenzo[1,4]oxazin-4-yl)-4-oxo-2-butenoic acid ethyl ester 6,8-Dimethyl-3,4-dihydro-2H-benzo[1,4]oxazine (208 mg) was dissolved in ethyl acetate (4 mL), and pyridine (0.155 mL) and (E)-3-chlorocarbonyl acrylic acid ethyl ester (311 mg) obtained in step 1 of Example 36 were added. After stirring at room temperature for 5 days, the reaction mixture was washed successively with water and saturated brine, and dried over anhydrous sodium sulfate. The solvent was evaporated, and the obtained residue was purified by silica gel chromatography (n-hexane-ethyl acetate=4:1) to give the title compound (312 mg) as a colorless oil.
Stage #1: 2-isopropyl-6,8-dimethyl-4H-benzo[1,4]oxazin-3-one With borane-THF In tetrahydrofuran for 1h; Heating / reflux;
Stage #2: With hydrogenchloride; water In tetrahydrofuran at 50℃; for 1h;
step 1 Production of 6,8-dimethyl-3,4-dihydro-2H-benzo[1,4]oxazine 6,8-Dimethyl-4H-benzo[1,4]oxazin-3-one (266 mg) obtained in step 2 of Example 82 was dissolved in tetrahydrofuran (5 mL), and a borane-tetrahydrofuran complex (1.0 M tetrahydrofuran, solution, 2.25 mL) was added. After heating under reflux for 1 hr, 1N hydrochloric acid was added to the reaction mixture, and the mixture was further stirred with heating at 50° C. for 1 hr. Water and ethyl acetate were added to the reaction mixture, and the mixture was extracted with ethyl acetate. The obtained ethyl acetate layer was washed with saturated brine, and dried over anhydrous magnesium sulfate. The solvent was evaporated, and the obtained residue was purified by silica gel chromatography (n-hexane-ethyl acetate=5:1) to give the title compound (213 mg) as a yellow oil.