The cresol black drug is formed by the action of cresol and phosphorus pentasulfide . The reaction formula is as follows:
The synthesis conditions and results are shown in the table. It can be seen from the table that when the reaction temperature is lower than 100 ° C, the reaction proceeds slowly or not at all (Test 1); when the reaction temperature is 100-110 ° C, a black drug with sufficient activity can be obtained (Test 6). However, the reaction proceeded slowly (190 minutes); at the reaction temperature of 120-140 ° C, the same results as above were obtained, and the reverse time was shortened, and the temperature was increased and the reaction rate was accelerated (tests 4, 7, 10). After the reaction is completed, heating at 170-180 ° C for two hours, the quality of the reaction product is greatly reduced (tests 9, 5, 11, 21, 24), it can be seen that the synthesis temperature is 120-140 ° C, the temperature is too high to produce dimethyl The phenolic dithiophosphoric acid will decompose.
When the pharmaceutical factory produces cresol black medicine, as long as the reaction material is heated to 130 ° C under stirring, the qualified product can be discharged, and the temperature of the product can be lowered to room temperature after a relatively long period of time in the storage. Therefore, it does not need to be heated for 2 hours.
Synthesis and Analysis of Cresol Black Medicine
test Numbering | Preparation conditions | | | | | Xylenol dithiophosphoric acid content (%) |
Participate in the weight of the reaction substance (g) | temperature reflex (°C) | Reaction time (Minute) | Heating time after reaction (minutes) | Heating temperature (°C) |
1 6 8 9 3 4 5 7 10 11 | Cresol 15.0; CP 2 S 5 5.0 .. .. .. .. .. .. .. .. .. | 50-60 100-110 100-110 100-110 120 120 120 140 140 140 | Reaction does not proceed 190 190 190 105 105 105 55 55 55 | - 0 120 120 0 120 120 0 120 120 | - - 120 170-180 - 120 170-180 - 120 170-180 | - 53.2 58.8 50.7 48.6 55.4 34.9 54.0 56.7 44.8 |
20 19 twenty one | Cresol 13.0; CP 2 S 5 5.8 .. .. | 120 120 120 | 105 105 105 | 0 120 120 | - 120 170-180 | 75.3 74.9 29.5 |
twenty two twenty three twenty four | Cresol 13.02; CP 2 S 5 6.0 .. | 120 120 120 | 55 55 55 | 0 120 120 | - 120 170-180 | 70.6 60.6 59.9 |
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