Triethylamine → 3-oxo-1-cyclohexen-1-yl 2,3-dihydrospiro[4H-1-benzothiopyran-4,2'-[1,3]dioxolane]-6-carboxylate 1,1-dioxide

Temperatur

0 °C

2.0 g (7.0 mmol) of the title compound of Step E, 1.2 mL (0.014 mol) of oxalyl chloride (purchase from Janssen), and 2 drops of N,N-dimethylformamide were added to 50 mL of methylene chloride. The mixture was refluxed under nitrogen for 2 h, and was then evaporated to dryness. 50 mL of methylene chloride was added to the residue and the resulting mixture was evaporated to dryness. Another 50 mL of methylene chloride was added to the residue, and the solution was cooled to about 0° C. 0.86 g (7.7 mmol) of 1,3-cyclohexanedione (purchased from Aldrich Chemical Company) was added followed by 2.7 mL (0.0196 mol) of triethylamine, and the mixture was stirred overnight while warming to room temperature. The mixture was evaporated to dryness, the residue was stirred in 100 mL of water and filtered. The crude product was washed with hexane to yield 2.19 g of the title compound of Step F as a solid melting at 185-186° C. 1H NMR (CDCl3): δ2.2 (m,2H), 2.5 (t,2H), 2.7 (t,4H), 3.7 (m,2H), 4.2 (m,2H), 4.3 (m,2H), 6.0 (s,1H), 8.0-8.25 (3H).

1. temperatureThe mixture was refluxed under nitrogen for 2 h
2. customwas then evaporated to dryness
3. addition50 mL of methylene chloride was added to the residue
4. customthe resulting mixture was evaporated to dryness
5. additionAnother 50 mL of methylene chloride was added to the residue
6. temperaturewhile warming to room temperature
7. customThe mixture was evaporated to dryness
8. stirringthe residue was stirred in 100 mL of water
9. filtrationfiltered
10. washThe crude product was washed with hexane

ORD-Eintrag

ord-adb458926fd74e01affac2a5d17300b9

Quelldatensatz

uspto-grants-1999_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05952266