反应详情

A clean dry reactor of 20 gallon capacity (91 liters) was charged with pyridine (7.0 kg.) followed by dimethylformamide (35.5 kg.). With agitation, benzoin (18.80 kg.) and succinic anhydride (16.0 kg.) were added. The reactor was flushed with nitrogen. Under a continuing atmosphere of nitrogen, the mixture was heated to 90°-95° C. and maintained within this temperature range for 2 hours. The reaction mixture was cooled to 35°-40° C. After twenty minutes, the reaction mixture was tranferred gradually over 5 hours to a mixture of water (190 kg.) and hydrochloric acid of specific gravity 1.18 (28 kg.) at 55°-60° C. in a reactor of 50 gallon capacity (227 liters). The temperature was maintained at 50°-60° C. over the 5 hour period. Dimethylformamide (9.0 kg.) was used for washing through. The mixture was cooled slowly until product crystallised and then to 15° to 20° C. The mixture was stirred overnight at 15° to 20° C. The product was filtered on a ceramic filter and sucked well dry. The product was then washed with water ten times with 20 kg. each time. Ater each wash portion the product was sucked well dry. The product was then dried in a circulating air oven at 50°-60° C. for 12 to 18 hours. The yield obtained was 25.5 kg.

1. customThe reactor was flushed with nitrogen
2. temperatureUnder a continuing atmosphere of nitrogen, the mixture was heated to 90°-95° C.
3. temperaturemaintained within this temperature range for 2 hours
4. temperatureThe reaction mixture was cooled to 35°-40° C
5. waitAfter twenty minutes
6. additionthe reaction mixture was tranferred gradually over 5 hours to a mixture of water (190 kg.) and hydrochloric acid of specific gravity 1.18 (28 kg.) at 55°-60° C. in a reactor of 50 gallon capacity (227 liters)
7. temperatureThe temperature was maintained at 50°-60° C. over the 5 hour period
8. washfor washing through
9. temperatureThe mixture was cooled slowly until product
10. customcrystallised
11. customto 15° to 20° C
12. filtrationThe product was filtered on
13. filtrationa ceramic filter
14. customsucked well dry
15. washThe product was then washed with water ten times with 20 kg
16. customAter each wash portion the product was sucked well dry
17. customThe product was then dried in a circulating air oven at 50°-60° C. for 12 to 18 hours
18. customThe yield obtained