Formic Acid → HCID 59228918, compound

Temperature

10 °C

Into a three-necked flask having an inner volume of 500 mL equipped with a stirrer, a thermometer and a dropping funnel, the whole amount of “Concentrated Liquid F” obtained above was charged, and cooled down to 10° C. 99% Formic acid (30.0 g, 0.645 mol) was weighed into a dropping funnel, and added dropwise to the reaction system so that the inner temperature of the reaction system was maintained in a range of 15 to 18° C. After that, the inner temperature was raised up to 34 to 35° C. by heating, and then 30% hydrogen peroxide aqueous solution (45.2 g, 0.399 mol) weighed and contained in another dropping funnel was added dropwise to the reaction system over 3 hours. After completion of the dropping, the inner temperature of the reaction system was also maintained at around 35° C. After 40 hours from completion of the dropping, the reaction liquid was analyzed by HPLC to confirm that conversion ratio of sodium 7-oxa-5-bornene-2-sulfonate was 98.1%. After cooling down the reaction liquid to 20° C., sodium sulfite was added slowly to the reaction system so that the inner temperature of the reaction system was maintained in a range of 20 to 25° C. until a starch paper did not detect hydrogen peroxide. Subsequently, 30% sodium hydroxide aqueous solution was added slowly to adjust pH of the reaction liquid at 6.8 so that the inner temperature of the reaction system was maintained in a range of 20 to 25° C. The reaction liquid was extracted with ethyl acetate (100 g) three times, and the resultant organic layers were combined, washed with water (50 g), and then concentrated under the reduced pressure until forming of white solid could be seen. Ethyl acetate (20 g) was added, and then isopropyl ether (40 g) as also added in a heated state at 60° C., then the mixture was cooled down to 1° C. at a rate of about 15° C./hour, to precipitate crystal of the product. After filtering the precipitated crystal, the filtered out crystal was washed with isopropyl ether (40 g) at 1° C., and dried at 30° C. for 2 hours under the reduced pressure, to obtain 2-hydroxy-4,8-dioxa-5-thiatricyclo[4.2.1.03,7]nonane 5,5-dioxide (6.84 g, purity: 98.9%, 0.035 mol). It should be noted that, yield of the product from 7-oxa-5-norbornene-2-sulfonyl chloride was 14.2%.

1. customInto a three-necked flask having
2. customan inner volume of 500 mL equipped with a stirrer
3. concentrationa thermometer and a dropping funnel, the whole amount of “Concentrated Liquid F”
4. customobtained above
5. additionwas charged
6. additionadded dropwise to the reaction system so that the inner temperature of the reaction system
7. temperaturewas maintained in a range of 15 to 18° C
8. temperatureAfter that, the inner temperature was raised up to 34 to 35° C.
9. temperatureby heating
10. customcontained in another dropping funnel
11. additionwas added dropwise to the reaction system over 3 hours
12. temperatureAfter completion of the dropping, the inner temperature of the reaction system was also maintained at around 35° C
13. customthe reaction liquid
14. temperatureAfter cooling down
15. customthe reaction liquid to 20° C.
16. custompH of the reaction liquid at 6.8 so that the inner temperature of the reaction system
17. temperaturewas maintained in a range of 20 to 25° C
18. customThe reaction liquid
19. extractionwas extracted with ethyl acetate (100 g) three times
20. washwashed with water (50 g)
21. concentrationconcentrated under the reduced pressure
22. customuntil forming of white solid
23. temperaturethe mixture was cooled down to 1° C. at a rate of about 15° C./hour
24. customto precipitate crystal of the product
25. filtrationAfter filtering the precipitated crystal
26. filtrationthe filtered out crystal
27. washwas washed with isopropyl ether (40 g) at 1° C.
28. customdried at 30° C. for 2 hours under the reduced pressure

ORD record

ord-d5d74a79a9cf41f9aa4243ba6c6ccf5d

Source dataset

uspto-grants-2013_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08367849B2