Ethyl Acetate → HCID 18924164, compound

Participants

Reaction Conditions

Reaction Steps

Methyl 2,3,3,3-tetrafluoropropanoate (27.0 g) was dissolved in dry dichloromethane and the solution stirred under a dry nitrogen atmosphere at 0° C. A one molar solution of di-n-butylboron trifluoromethanesulfonate in dichloromethane (190 ml) was added in portions over 15 minutes. After a further 15 minutes, the temperature was reduced to -10° C. and di-isopropylethylamine (35 ml) was added in portions, then stirring was continued for a further 2 hours. Paraformaldehyde (100 g) (previously dried under vacuum over P2 O5) was heated to 180°-200° C. and the resulting formaldehyde was passed into the reaction mixture in a stream of dry nitrogen, keeping the temperature close to -10° C. After 30 minutes, the mixture was poured into a mixture of 30% aqueous hydrogen peroxide (150 ml) pH7 phosphate buffer (600 ml) and crushed ice, and was stirred at 0° C. for 45 minutes. The mixture was extracted with dichloromethane (3×200 ml). The combined extracts were washed with sodium disulphite solution, dried (MgSO4) and concentrated under reduced pressure to leave a yellow oil, which was redissolved in ethyl acetate and filtered through a thick plug of silica gel, and then was again concentrated under reduced pressure. The crude product was purified by chromatography on silica, eluting with 25% ethyl acetate in hexane. Subsequent heating to 65° C. under aspirator vacuum (20 mmHg) gave the product as a yellow oil (4.8 g); 1H NMR (270 MHz; CDCl3) δ 3.93(3H,s), 4.05-4.30(2H,m), 2.80(1H,bt) ppm.

Provenance & Evidence