Dimethylformamide → 2-Dimethylaminomethylene-4-acetamidocyclohexanone

A reaction mixture was prepared from 15.5 g. of 4-acetamidocyclohexanone [prepared by the procedure of Fraser and Swingle, Can. J. Chem., 48, 2065 (1970)], 80 g. of the dimethylacetal of dimethylformamide, 1.5 ml. of triethylamine and 500 ml. of benzene. The benzene was distilled therefrom over a 1.5 hour period until the volume was reduced to about 1/2 of the original volume. An additional 250 ml. of benzene were added. The reaction mixture was heated just below the boiling point of benzene for about 2 hours and was then distilled again until the volume was about one-half of that originally present (250 ml.) The above process was repeated once more except that the volume was reduced to one-third of the original volume (167 ml.). The reaction mixture was then cooled and filtered. The filter cake consisted of dl-4-acetamido-2-dimethylaminomethylenecyclohexanone formed in the above reaction; weight=6.45 g. Evaporation of the filtrate to dryness yielded a residue, chromatography of a chloroform solution of which over 200 g. of Florisil using chloroform containing increasing amounts of methanol (0-5%) as an eluant, yielded more dl-4-acetamido-2-dimethylaminomethylenecyclohexanone; M.P.=132°-133° C. (from benzene); yield=5.55 g.; total yield=12 g.

1. customA reaction mixture was prepared from 15.5 g
2. distillationThe benzene was distilled
3. additionof benzene were added
4. temperatureThe reaction mixture was heated just below the boiling point of benzene for about 2 hours
5. distillationwas then distilled again until the volume
6. temperatureThe reaction mixture was then cooled
7. filtrationfiltered
8. customformed in the above reaction
9. customEvaporation of the filtrate to dryness
10. customyielded a residue, chromatography of a chloroform solution of which over 200 g

ORD record

ord-27fff368ac79464ca49b586aba6b0c93

Source dataset

uspto-grants-1980_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04235776