Sulfuric Acid → CID 3084433

Temperature

-20 °C

In the same reaction apparatus as in Example 1, 150 g of 25% fuming sulfuric acid was dropwise added over a period of one hour to 500 g of tetrahydrofuran while being maintained at -20° C., and after completion of the dropwise addition, the mixture was further subjected to reaction at -20° C. for 10 minutes. The conversion at this point was 14%. Then, the reaction temperature was elevated to 30° C. and the reaction was continued for one hour. The conversion at the end of this reaction was 47%. Neither solidification nor coloration of the reaction system was observed throughout the period of the reaction. Then, 180 g of ion exchanged water was added to the reaction mixture with stirring well to terminate the reaction, followed by addition of 145 g of a 45% by weight sodium hydroxide solution to neutralize a part of the sulfuric acid. After replacing the dropping funnel by a distilling column, the reaction mixture was heated in an oil bath at 95° C. for 2 hours to perform the hydrolysis of the polymerization product terminals while distilling off unreacted tetrahydrofuran. After completion of the reaction, the reaction product was allowed to stand at room temperature to cool the same. The separated aqueous layer was withdrawn and the residual oil layer was treated in the same manner as in Example 1 to obtain colorless liquid PTMG. The analytical results of the product and the catalytic efficiency α were as shown in Table 1.

1. additionafter completion of the dropwise addition
2. customthe mixture was further subjected to reaction at -20° C. for 10 minutes
3. customwas elevated to 30° C.
4. customNeither solidification nor coloration of the reaction system was observed throughout the period of the reaction
5. additionwas added to the reaction mixture
6. customto terminate
7. customthe reaction
8. temperaturethe reaction mixture was heated in an oil bath at 95° C. for 2 hours
9. customthe hydrolysis of the polymerization product terminals
10. distillationwhile distilling off unreacted tetrahydrofuran
11. customAfter completion of the reaction
12. customto stand at room temperature
13. temperatureto cool the same
14. customThe separated aqueous layer was withdrawn
15. additionthe residual oil layer was treated in the same manner as in Example 1

ORD record

ord-e82c00607d324e19bcf8375410e75291

Source dataset

uspto-grants-1983_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04371713