preparation of 2,3-dichlorotetrahydrofuran_industrial additives

preparation background and overview of 2,3-dichlorotetrahydrofuran

2,3-dichlorotetrahydrofuran is similar to tetrahydrofuran. it is a widely used organic solvent. it can dissolve almost all polymers except polyethylene, polypropylene and fluororesin. it is especially suitable for polyethylene, polyvinylidene resin and styrene-butadiene rubber. in organic synthesis, 2,3-dichlorotetrahydrofuran is often used as a solvent. in addition, the demand for 2,3-dichlorotetrahydrofuran as a binder is also large. 2,3-dichlorotetrahydrofuran is also used in the precision tape industry. tetramethylene ether glycol, a polymer of 2,3-dichlorotetrahydrofuran, is the raw material for the synthesis of polychloronitrogen elastic fibers and polyurethane elastomers.

preparation of 2,3-dichlorotetrahydrofuran

1. preparation of hydrogenation catalyst

put 52.2g cu(no3)2.3h2o (product of beijing chemical plant, chemically pure), 23.2g 50% mn(no3)2. aqueous solution (product of beijing chemical plant, chemically pure), 8.1g al(no3)3.9h2o (beijing chemical plant product, chemically pure) was dissolved in 600 ml of deionized water, stirred at 50°c tetrahydrofuranthiol; 1°c, and 12wt% ammonia water (beijing chemical plant product, chemically pure) was added dropwise until the ph of the solution was 5.5±0.5, aged 1 hour, then filter, wash with water once, collect the precipitate, dry at 200°c for 2 hours, and calcine at 500°c for 2 hours to obtain catalytic a: cumn0.15al0.1o1.3.

2. preparation of eta-al2 difluorophenylboronic acid o3 catalyst

put 50g of mixed hydrous alumina containing diaspore and diaspore (70% of which is diaspore) in a muffle furnace and roast it at ℃ for 4 hours to obtain eta-al2o3 catalyst d, with a specific surface area 215m2/g, pore volume 0.57ml/g.

3. preparation of tetrahydrofuran

using dimethyl maleate as the raw material, catalyst a as the first stage catalyst, the hydrogenation reaction conditions are 189±1°c, 5.8±0.2mpa, h2/ester 269:1 (mol), the hourly space velocity of the raw material liquid is 1.8 react under conditions of h-1, catalyst d is the second stage catalyst, reaction conditions are 300±2°c, 0.1mpa, liquid hourly space velocity 90h-1, and the obtained product is tetrahydrofuran.

4.preparation of 2,3-dichlorotetrahydrofuran

2,3-dichlorotetrahydrofuran was synthesized using sulfuryl chloride and tetrahydrofuran as raw materials and carbon tetrachloride as solvent. the optimized reaction conditions are: 1.4 mol of tetrahydrofuran, 1 mol of sulfuryl chloride, and 50 ml of carbon tetrachloride. the reaction is carried out at 65-75°c for 1 hour. the yield reaches 79.3℅. the purity of the product is 95.6 after gas chromatography analysis. ℅, and confirmed the chemical structure of the product through ir, hnmr and gc-ms.