Hydrogen-containing double capsule (134.0g, 1mol) and octamethylcyclotetrasiloxane (519g,1.75mol) mixture was added dropwise to a vigorously stirred 10% solution of potassium hydroxide in water and toluene to control the temperature to within 50 degrees Celsius, dropwise, continue to react for 2h, GC detection of the reaction was completed, static, partitioning, the organic layer was washed once with water, saturated ammonium chloride, saturated saline water, anhydrous Sodium sulfate drying, distillation, collection of 112-114 degrees, 15 torr fraction, to get intermediate (7) (227g ,35%), GC analysis purity 95%. Intermediate (7) (327g,0.5mol), anhydrous aluminum trichloride (0.7g,5mmol) in a 500ml three-necked flask with a thermometer, dropping funnel and condenser tube, heated to 40 degrees and then add acetyl chloride (47g,0.6mol) dropwise, dropping is exothermic, control the temperature at 65 degrees or less, dropwise, continue to react for 0.5h, GC detection reaction is complete. Cooling, distillation, collection of 130 degrees, 15 torr fraction, to get colorless transparent liquid intermediate (8) (314g ,86%), GC analysis purity of 98%. Intermediate (8) (131g,0.2mol) dissolved in 100m1 ether, added dropwise to a mixture of 5% aqueous sodium bicarbonate and ether with vigorous stirring, dropwise system exothermic, and there is solid precipitation, control the temperature within 30 degrees Celsius, dropwise, the reaction at room temperature overnight, GC detection reaction is complete, liquid separation, washing, saturated saline water washed anhydrous sodium sulfate drying, concentration, obtained Colorless transparent liquid octadecamethyl cyclic nine siloxane (D9) (54g, 43%).
