Trifluoromethanesulfonyl chloride → Ethyl 4-methyl-2-(trifluoromethanesulfonyloxy)cyclohex-1-enecarboxylate

To a solution of ethyl 4-methyl-2-cyclohexanone-1-carboxylate (50 g, 0.27 mol) in dichloromethane (500 ml) at −10° C. was added N,N-diisopropylethylamine (52 ml, 0.3 mol) followed by dropwise addition of trifluoromethanesulphonyl chloride (57 ml, 0.3 mol) keeping the temperature between −5 and −100° C. The reaction mixture was allowed to warm to room temperature and stirred for 3 hours. TLC showed 80% reaction, it was cooled to −5° C. and more N,N-diisopropylethylamine (14 ml, 0.1 mol) was added followed by trifluoromethanesulphonyl chloride (15.5 ml, 0.1 mol) and the reaction mixture was stirred for 15 hours at room temperature. The mixture was washed with cold water (2×200 ml), cold saturated sodium bicarbonate (2×200 ml) and brine (1×200 ml). The organic layer was dried (MgSO4), filtered and evaporated to give the required product (85 g) as a colourless oil. 1H NMR (250 MHz, CDCl3) δ 1.04 (3H, d, J=6.5 Hz), 1.43 (3H, m), 1.73-2.09 (4H, m), 2.39-2.63 (3H, m), 4.25 (2H, m).

1. customthe temperature between −5 and −100° C
2. custom80% reaction, it
3. temperaturewas cooled to −5° C.
4. stirringthe reaction mixture was stirred for 15 hours at room temperature
5. washThe mixture was washed with cold water (2×200 ml), cold saturated sodium bicarbonate (2×200 ml) and brine (1×200 ml)
6. dry with materialThe organic layer was dried (MgSO4)
7. filtrationfiltered
8. customevaporated

ORD record

ord-4074c702c7ca473097e8aa98fb7a7bcb

Source dataset

uspto-grants-2001_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06255305B1