Formaldehyde → 2-[(Ethylsulfanyl)methyl]prop-2-enoic acid

Temperature

70 °C

A mixture of malonic acid (5.2 g, 50 mmol), paraformaldehyde (3.3 g, 110 mmol), dicyclohexylamine, 9.95 ml, 50 mmol) and ethanethiol 4.06 ml, 55 mmol) in dioxane (120 ml) was heated at 70° C. for 2 hours. The solvents were removed under reduced pressure, the residue was redissolved in ethyl acetate and the solution was extracted with saturated aqueous sodium hydrogen carbonate (4×20 ml). The combined aqueous layers were washed with ethyl acetate (20 ml) then acidified with 1 M hydrochloric acid. The resulting suspension was extracted into dichloromethane and the solution was dried over anhydrous magnesium sulfate, filtered and evaporated to provide the title compound as a white solid (3.76 g, 52%). 1H-NMR; δ (CDCl3), 9.89 (1H, br s), 6.35 (1H, s), 5.77 (1H, s), 3.39 (2H, s), 2.49 (2H, dd, J=7.4, 14.5 Hz) and 1.25 (3H, t, J=5.2 Hz).

1. customThe solvents were removed under reduced pressure
2. dissolutionthe residue was redissolved in ethyl acetate
3. extractionthe solution was extracted with saturated aqueous sodium hydrogen carbonate (4×20 ml)
4. washThe combined aqueous layers were washed with ethyl acetate (20 ml)
5. extractionThe resulting suspension was extracted into dichloromethane
6. dry with materialthe solution was dried over anhydrous magnesium sulfate
7. filtrationfiltered
8. customevaporated

ORD record

ord-4271d863b26b402c9facb1a2b299c343

Source dataset

uspto-grants-2002_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06423690B1