Water → HCID 19771711, compound

Temperature

120 °C

A solution of tetrahydrothiopyran-4-one (20.0 g), morpholine (15.0 g) and p-toluenesulphonic acid (200 mg) in toluene (100 ml) was heated under reflux for 24 hours with azeotropic removal of water. Volatile material was removed by evaporation and the residue was heated with 5-(1-hydroxypropylidene)-2,2-dimethyl-1,3-dioxane-4,6-dione (68 g) at 120° C. for 3 hours. The mixture was dissolved in dichloromethane (300 ml) and the solution was washed with 2M sodium hydroxide solution (2×100 ml), water (2×100 ml) and saturated sodium chloride solution (100 ml). The organic phase was then dried (MgSO4) and volatile material was removed by evaporation. The residue was purified by flash chromatography, eluting with ethyl acetate/hexane (1:1 v/v), to give 7,8-dihydro-2-ethyl-thiopyrano[4,3-b]pyran-4(5H)-one (B) (9.2 g), as an oil; NMR (CDCl3) 1.2(t, 3H). 2.55(q, 2H), 2.8-2.9(m, 4H), 3.55(s, 2H), 6.1(s, 1H).

1. customVolatile material was removed by evaporation
2. dissolutionThe mixture was dissolved in dichloromethane (300 ml)
3. washthe solution was washed with 2M sodium hydroxide solution (2×100 ml), water (2×100 ml) and saturated sodium chloride solution (100 ml)
4. dry with materialThe organic phase was then dried (MgSO4) and volatile material
5. customwas removed by evaporation
6. customThe residue was purified by flash chromatography
7. washeluting with ethyl acetate/hexane (1:1 v/v)

ORD record

ord-12dcd9e2cb7a48a6aa6f9b3e3bf2fff6

Source dataset

uspto-grants-1993_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05198434