3-chloropropyl(triethoxy)silane

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 27.5 g (417 mmol) of freshly distilled cyclopentadiene are added dropwise to a suspension of 15 g (417 mmol) of sodium hydride in 250 ml of absolute tetrahydrofuran at room temperature over a period of one hour. 100.3 g of (3-chloropropyl)triethoxysilane are subsequently added dropwise over a period of 30 minutes. The solution becomes warm during this process. After taking off the solvent, the mixture is fractionally distilled in an oil pump vacuum to give 96.1 g of (3-cyclopenta-dienylpropyl)triethoxysilane (yield: 90%). The solution becomes warm during this process the mixture is fractionally distilled in an oil pump vacuum

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: This example illustrates the preparation of a thiocarboxylate alkoxysilane from a salt of a thiolcarboxylic acid using as a solvent the alcohol corresponding to the silane alkoxy group. Into a 250 ml, three-neck round bottomed flask equipped with magnetic stir bar, temperature probe/controller, heating mantle, addition funnel, condenser, and N2 inlet was charged 63 grams of a 21 weight percent sodium ethoxide in ethanol. Fifteen grams of thiolacetic acid was added slowly, keeping the temperature below 65° C. The solution was allowed to cool to room temperature, and 48 grams of chloropropyltriethoxysilane was added via the addition funnel. After addition was complete, the solution was heated to 70° C. for 24 hours whereupon a white solid formed. Analysis of the solution by gas chromatography showed a 78 percent yield of acetylthiopropyltriethoxysilane. Into a 250 ml, three-neck round bottomed flask equipped with magnetic stir bar temperature probe/controller, heating mantle addition funnel, condenser, and N2 inlet the temperature below 65° C After addition the solution was heated to 70° C. for 24 hours whereupon a white solid formed

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A suitable method for the preparation of bis-[γ-(trialkoxysilyl)-propyl]-disulfides is disclosed in copending application Ser. No. 529,203 filed Dec. 3, 1974 entitled "Bis-[γ-(Trialkoxysilyl)-Propyl]-Disulfides of High Purity", the disclosure of which is hereby incorporated specifically herein by reference. According to the process therein disclosed such a disulfide can be prepared by reacting a γ-chloropropyl-triethoxy silane with thiourea and sodium iodide in alcohol for 24 hours at ebullition. After the reaction mixture is cooled to room temperature and over a period of 4 hours a strong current of ammonia is passed through the solution. This causes ammonium chloride to precipitate. The filtrate and precipitate are separated and the filtrate can be concentrated whereby to obtain γ-mercaptopropyl-triethoxy silane. This latter material can be reacted with sulfuryl chloride in a solvent such as anhydrous benzene at a temperature of +8 - + 12°C. The SO2Cl2 is added to the γ-mercapto-propyl-triethoxy silane dropwise over a period of about 55 minutes. Sulfur dioxide and hydrogen chloride gas which are formed are removed by a nitrogen gas purge. After a period of about 6 hours at room temperature with stirring triethylamine can be added whereby to precipitate the amine hydrochloride. The filtrate is then fractionally distilled whereby there is recovered a bis-[γ-(triethoxysilyl)-propyl]-disulfide. can be prepared for 24 hours This causes ammonium chloride to precipitate The filtrate and precipitate are separated the filtrate can be concentrated whereby

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A suitable method for the preparation of bis-[γ-(trialkoxysilyl)-propyl]-disulfides is disclosed in copending application Ser. No. 529,203 filed Dec. 3, 1974 entitled "Bis-[γ-(Trialkoxysilyl)-Propyl]-Disulfides of High Purity", the disclosure of which is hereby incorporated specifically herein by reference. According to the process therein disclosed such a disulfide can be prepared by reacting a γ-chloropropyl-triethoxy silane with thiourea and sodium iodide in alcohol for 24 hours at ebullition. After the reaction mixture is cooled to room temperature and over a period of 4 hours a strong current of ammonia is passed through the solution. This causes ammonium chloride to precipitate. The filtrate and precipitate are separated and the filtrate can be concentrated whereby to obtain γ-mercaptopropyl-triethoxy silane. This latter material can be reacted with sulfuryl chloride in a solvent such as anhydrous benzene at a temperature of +8 - + 12°C. The SO2Cl2 is added to the γ-mercapto-propyl-triethoxy silane dropwise over a period of about 55 minutes. Sulfur dioxide and hydrogen chloride gas which are formed are removed by a nitrogen gas purge. After a period of about 6 hours at room temperature with stirring triethylamine can be added whereby to precipitate the amine hydrochloride. The filtrate is then fractionally distilled whereby there is recovered a bis-[γ-(triethoxysilyl)-propyl]-disulfide. can be prepared for 24 hours This causes ammonium chloride to precipitate The filtrate and precipitate are separated the filtrate can be concentrated whereby

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 129 l of ethanol and 129 l of 3-chloropropyltriethoxysilane is placed in the reactor of comparison example 1. 13.85 kg of sulfur in the form of a powder are metered in. 35.6 kg of virtually anhydrous sodium sulfide is then added. The temperature of the reactor contents rises to 82° C. on account of the exothermic reaction. The reaction mixture is kept for a further 1.5 hours at 82-83° C. and then cooled. The reaction mixture is worked up as in comparison example 1. An almost water-white product is obtained. HPLC analysis confirms in this case too the presence of a polysulfane mixture with a mean chain length of 2, though the mixture has a high monosulfane content. The temperature of the reactor contents rises to 82° C. on account of the exothermic reaction cooled

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 129 l of ethanol and 129 l of 3-chloropropyltriethoxysilane is placed in the reactor of comparison example 1. 13.85 kg of sulfur in the form of a powder are metered in. 35.6 kg of virtually anhydrous sodium sulfide is then added. The temperature of the reactor contents rises to 82° C. on account of the exothermic reaction. The reaction mixture is kept for a further 1.5 hours at 82-83° C. and then cooled. The reaction mixture is worked up as in comparison example 1. An almost water-white product is obtained. HPLC analysis confirms in this case too the presence of a polysulfane mixture with a mean chain length of 2, though the mixture has a high monosulfane content. The temperature of the reactor contents rises to 82° C. on account of the exothermic reaction cooled