Pyridine → 4-tert-Butyl-5-methyl-2H-1,3-dioxol-2-one

Forty-four g of a 12.5% solution of phosgene in toluene is added over 30 min to a well stirred solution of 4,4-dimethyl-2-hydroxy-3-pentanone (4.85 g, 37.3 mmol) in toluene, 90 ml, at 0°-5° C. Following this addition, a solution of pyridine, 11.4 ml, in toluene, 25 ml, is then added to the cooled reaction mixture over 30 min. After stirring at 20°-25° C. for 20 hours, the reaction mixture is washed with 3N HCl and water saturated with NaCl. The toluene extract is dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. After addition of p-toluenesulfonic acid hydrate, 100 mg, to the residue, it is stirred neat at 160° C for 24 hours. The resulting black liquid is dissolved in ethyl acetate, washed with a saturated sodium bicarbonate solution and a saturated sodium chloride solution and dried over anhydrous sodium sulfate. After filtering and concentrating under reduced pressure, the residue is distilled to give 3.5 g of product, bp 82°-4° C. at 3mm.

1. customat 0°-5° C
2. additionthis addition
3. washthe reaction mixture is washed with 3N HCl and water saturated with NaCl
4. extractionThe toluene extract
5. dry with materialis dried over anhydrous sodium sulfate
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure
8. additionAfter addition of p-toluenesulfonic acid hydrate, 100 mg
9. stirringto the residue, it is stirred neat at 160° C for 24 hours
10. dissolutionThe resulting black liquid is dissolved in ethyl acetate
11. washwashed with a saturated sodium bicarbonate solution
12. dry with materiala saturated sodium chloride solution and dried over anhydrous sodium sulfate
13. filtrationAfter filtering
14. concentrationconcentrating under reduced pressure
15. distillationthe residue is distilled

ORD record

ord-49e343aea3c74f9c8e7d3c1975d21466

Source dataset

uspto-grants-1987_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04654331