Hydrochloric Acid → 4-Ethylquinolin-2(1H)-one

Temperature

-10 °C

1,2-Dihydro-4-methyl-2-oxoquinoline (79.5 g.) was dissolved in a mixture of dry hexamethylphosphoramide (530 ml.) and tetrahydrofuran (530 ml.), and the solution was cooled to -10° C. under a nitrogen atmosphere. n-Butyl-lithium (1.54 M solution in hexane; 770 ml.) was added to the stirred solution at such a rate as to keep the temperature below 0° C. When the addition was completed, the deep red solution was cooled to -50° C. and methyl iodide (50 ml.) was rapidly added. The resulting pale yellow solution was immediately poured into water (2000 ml.) and acidified to pH 1 with concentrated hydrochloric acid. The resulting mixture was filtered and the solid residue washed with water and then dried in vacuo over phosphorus pentoxide. Crystallisation from ethanol gave 4-ethyl-1,2-dihydro-2-oxoquinoline, m.p. 197° C.

1. customthe temperature below 0° C
2. additionWhen the addition
3. temperaturethe deep red solution was cooled to -50° C.
4. filtrationThe resulting mixture was filtered
5. washthe solid residue washed with water
6. dry with materialdried in vacuo over phosphorus pentoxide
7. customCrystallisation from ethanol

ORD record

ord-c1fd8fef4f074e9c8463d36fc2f46162

Source dataset

uspto-grants-1980_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04187310