Methyl iodide → HCID 13485798, compound

Temperature

20 °C

Potassium hydroxide (3.36 g, 60 mmoles) was added to a stirred solution of 5,6-dihydro-2H-pyran-2-one (4.9 g, 50 mmoles) in water (45 ml) at 5° C. The solution was allowed to warm to 20° C. and stirred for 21/2 hours then evaporated to residue in a vacuum. The residue was flushed with isopropanol (2×50 ml) and dried in a vacuum at 50° C. over P2O5. This solid was slurried in dry dimethylformamide (30 ml) and methyl iodide (34.2 g, 240 mmol) added. The slurry was stirred for 18 hours at 20° C. then quenched by the addition of ice (20 g). The mixture was extracted with diethyl ether (4×50 ml) and the extracts washed with aqueous sodium chloride (50 ml) and dried (Na2SO4). Solvent removal in a vacuum afforded methyl (Z)-5-hydroxy-2-pentenoate as a colourless oil (4.1 g, 63% yield). The oil was dissolved in dichloromethane (40 ml) with N,N-dimethylaminopyridine (0.1 g) and treated with acetyl chloride (2.75 g, 35 mmoles) in dichloromethane (10 ml) added over 5 minutes at 5° C. The resulting slurry was allowed to warm to room temperature then quenched by the addition of water (40 ml) and the layers separated. The aqueous layer was extracted with dichloromethane (40 ml) and the organic extracts combined, washed with hydrochloric acid (0.5M, 2×50 ml) then water (2×50 ml), and dried (Na2SO4). Solvent removal in a vacuum followed by Kugelrohr distillation afforded methyl (Z)-5-acetoxy-2-pentenoate as a colourless oil (4.1 g, 76%) b.p. 75° C./0.1 mbar (Found: C, 55.60, H, 7.00 C8H12O4 requires C, 55.80; H, 7.00%).

1. customthen evaporated to residue in a vacuum
2. customThe residue was flushed with isopropanol (2×50 ml)
3. dry with materialdried in a vacuum at 50° C. over P2O5
4. stirringThe slurry was stirred for 18 hours at 20° C.
5. customthen quenched by the addition of ice (20 g)
6. extractionThe mixture was extracted with diethyl ether (4×50 ml)
7. washthe extracts washed with aqueous sodium chloride (50 ml)
8. dry with materialdried (Na2SO4)
9. customSolvent removal in a vacuum

ORD record

ord-c7f26141192c463db6e46a4ca08a972d

Source dataset

uspto-grants-1992_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05104989