Methyl Acrylate → Methyl 2,2-diMethyl-3-oxocyclobutanecarboxylate

The suspension of methyl acrylate (1.3 equiv.), 1-chloro-N,N,2-trimethylprop-1-en-1-amine (1.0 equiv.), and zinc trifluoromethanesulfonate (0.25 equiv.) was stirred to blend its contents for 15 min at room temperature under N2. Then the mixture was sonicated (100 W) at 36-39° C. for 24 h. A mixture of THF:H2O=10:1 was added to the mixture and sonicated. The mixture was concentrated and extracted with ethyl acetate. The combined organic layers were washed with brine, dried over anhydrous sodium sulfate and filtered. The filtrate was evaporated under reduced pressure and the residue was purified by silica gel chromatography (petroleum ether; petroleum ether:ethyl acetate=50:1, 10:1) to afford the title compound methyl 2,2-dimethyl-3-oxocyclobutanecarboxylate (29% yield) as a light yellow oil. 1H NMR (400 MHz, CDCl3) δ (ppm) 3.73 (s, 3H), 3.51 (dd, J=7.6 Hz, 18.4 Hz, 1H), 3.07 (q, J=9.2 Hz, 18 Hz 1H), 2.94 (t, J=7.2 Hz, 8.8 Hz, 1H), 1.29 (s, 3H), 1.09 (s, 3H).

1. customfor 15 min
2. customat room temperature
3. customThen the mixture was sonicated (100 W) at 36-39° C. for 24 h
4. customsonicated
5. concentrationThe mixture was concentrated
6. extractionextracted with ethyl acetate
7. washThe combined organic layers were washed with brine
8. dry with materialdried over anhydrous sodium sulfate
9. filtrationfiltered
10. customThe filtrate was evaporated under reduced pressure
11. customthe residue was purified by silica gel chromatography (petroleum ether; petroleum ether:ethyl acetate=50:1, 10:1)

ORD record

ord-699250b76e2840d3a1f8f732be721ace

Source dataset

uspto-grants-2015_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09156798B2