Dimethylformamide → 2,2-Dimethyl-2,3-dihydro-1-benzofuran-7-carbaldehyde

Temperature

0 °C

n-Butyl lithium, 2.7M, (25.04 ml, 0.0676 mole) was added to a stirred solution of 2,3-dihydro-2,2-dimethylbenzofuran (10.0 grams, 0.0676 mole) in tetrahydrofuran (75 ml) at -78° C. The reaction mixture was then stirred at 0° C. for two hours after which it was added to a cooled (-78° C.) solution of dimethylformamide (5.42 ml, 0.07 mole) in tetrahydrofuran (25 ml). Upon completion of addition, the reaction mixture was stirred at -78° C. for ten minutes and then warmed to ambient temperature. The reaction mixture was quenched with aqueous ammonium chloride (1M, 150 ml) and stirred for three hours at ambient temperature. The reaction mixture was extracted with diethyl ether (2×150 ml), and the combined extract was washed with a saturated aqueous solution of sodium chloride. The dried (magnesium sulfate) extract was concentrated under reduced pressure leaving a residue. This residue was distilled, yielding 3.72 grams of 2,3-dihydro-2,2-dimethylbenzofuran-7 -carboxaldehyde, b.p. 80°-83° C./0.2 mmHg. The NMR spectrum was consistent with the proposed structure.

1. additionwas added to
2. additionUpon completion of addition
3. stirringthe reaction mixture was stirred at -78° C. for ten minutes
4. temperaturewarmed to ambient temperature
5. customThe reaction mixture was quenched with aqueous ammonium chloride (1M, 150 ml)
6. stirringstirred for three hours at ambient temperature
7. extractionThe reaction mixture was extracted with diethyl ether (2×150 ml)
8. extractionthe combined extract
9. washwas washed with a saturated aqueous solution of sodium chloride
10. dry with materialThe dried (magnesium sulfate)
11. extractionextract
12. concentrationwas concentrated under reduced pressure
13. customleaving a residue
14. distillationThis residue was distilled

ORD record

ord-8854da6a2c6d40198d253789ff5e43da

Source dataset

uspto-grants-1988_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04748186