Bis(hexylene glycolato)diboron

White crystalline powde

HEXYLENEGLYCOL (2-methyl-2, 4-pentanediol) (FW: 118. 18. 12.0 g, 101. 6 mmol) in toluene (40 mL) was treated with tetrakis (dimethylamino) diboron (FW: 197.926 ; 9.9 g, 50 mmol) at room temperature and the reaction mixture stirred. The temperature was raised to 100 C within 10 minutes while the release of dimethylamine started to occur after about 5 minutes. The temperature was maintained at 100 C. for 60 minutes at which time for 30 minutes the evolution of dimethylamine occurred. Toluene was removed to give a solid (99.6percent pure by GC). The solid was recrystallised from toluene: petroleum (80 C-100 C) (1: 9) to give a colourless solid of bis (hexylene glycolato) diboron (MF: C12H24B204 ; FW : 253.94) : 8. 83 g, second crop: 3.69 g, combined yield 12.52 g, 98. 6percent; 99.6percent pure by GC. mp 99-101. 6 C. 8 (CDC13, 200 MHz) 1.21 (d, J= 7Hz, 6H); 1.28 (s, 12H); 1.47 (dd, J=12, 14 Hz, 2H); 1.70 (dd, J=14, 3 Hz; 2H) 4.14 (dm, 2H) ppm. 13C 8 (CDCL3, 50 MHz) 23.1 ; 28.3 ; 31.2 ; 46. 2 ; 64.1 ; 70.3 ppm.The first step: nitrogen protection, in the 5L reaction bottle, 0.4LBH3-Me2S (10M) and 2.0L dichloromethane, stirring evenly, the temperature to -10 to 0 deg C, slowly dropping 460g2-methyl -2, 4-pentanediol (3.9 mol) was dissolved in 0.5 L of dichloromethane. Attention to control the process of dropping the bubble in the reactor, the exhaust gas then sodium hypochlorite solution absorption, the reaction process of the release of dimethyl sulfide absorption into dimethyl sulfoxide. After the completion of the dropwise addition, the reaction was stirred for 3-5 hours. When the GC reaction was not changed, the methylene chloride was distilled off at atmospheric pressure. After adding 3 g of 2, 6-di-tert-butyl-4-methylphenol, the reaction temperature was raised Distillation gave 409 g of 2-methyl-2, 4-pentanediol borane as a colorless oily liquid, GC: 98.0percent, yield 82percent.(R = Me), 55 g of cyclooctene and 550 mL of toluene were mixed under nitrogen atmosphere, and the temperature was maintained until the system was weakly refluxed. 128 g of 2-methyl-2, 4-pentanedi Alcohol borane (1mol), drop finished, continue to reflux stirring reaction 15 hours. After the reaction was complete, the reaction mixture was cooled down, filtered through Celite, evaporated to dryness, and 220 mL of n-hexane solvent was added. The mixture was stirred at -10 ° C to -5 ° C for 1 to 2 hours and filtered to give 82.6 g of white crystalline bidentate -2, 4-pentanediol, GC: 98.4percent, yield 65percent.

suzuki reaction

Molecular Weight:253.9
Hydrogen Bond Acceptor Count:4
Rotatable Bond Count:1
Exact Mass:254.1860696
Monoisotopic Mass:254.1860696
Topological Polar Surface Area:36.9
Heavy Atom Count:18
Complexity:279
Undefined Atom Stereocenter Count:2
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes