A kind of preparation method of 7-dehydrocholesterol and vitamin D3
A technology for dehydrocholesterol and cholesterol, applied in the directions of steroids, organic chemistry, etc., can solve problems such as low yield of 7-dehydrocholesterol, and achieve the effects of shortening the reaction time of bromine, less environmental pollution and simple steps.
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[0043] The preparation method of 7-dehydrocholesterol provided by the invention comprises the following steps:
[0044] (1) carry out esterification reaction with cholesterol and benzoyl chloride, obtain cholesterol benzoate;
[0045] (2) the cholesteryl benzoate, bromine agent, initiator and acid-binding agent are dissolved in an organic solvent, and then the gradient temperature rise mode is adopted to carry out bromination reaction to obtain 7-bromocholesterol benzoate Bromination reaction product; the gradient temperature rise method is to naturally raise the temperature to 50°C, then raise the temperature from 50°C to 65°C at a rate of 0.3-1°C / min, and keep warm at each integer temperature point for 1-3 minutes during the process, and finally Incubate at 65°C for 2 to 5 minutes;
[0046] (3) carrying out debromination reaction with the bromination reaction product containing 7-bromocholesterol benzoate and an organic base to obtain 7-dehydrocholesterol benzoate;
[0047...
Embodiment 1
[0065] (1) Esterification reaction:
[0066] Take a 1L three-neck flask, add 215ml of toluene, 76.5g (0.19mol) of cholesterol, 30.6g (0.30mol) of triethylamine, and 0.5g of DMAP into the reaction flask, vacuumize and replenish nitrogen, and when the internal temperature rises to 45°C, start dripping Add 32.4 g (0.23 mol) of benzoyl chloride, control the dropwise addition time at 45 min, continue to raise the temperature to 80°C, and keep the reaction for 4 h. After the reaction is completed, add 80ml of water to quench the reaction, wash and extract three times, concentrate the oil layer, add 200ml of acetone to the concentrated substrate, reflux at 60°C for 30min, cool to room temperature, and filter to obtain cholesterol benzoate.
[0067] (2) bromine reaction:
[0068] Put 10g (0.02mol) of cholesterol benzoate obtained in step (1), 2.65g (0.0093mol) of DDH, 1.73g (0.02mol) of sodium bicarbonate, 100ml of petroleum ether, and 0.08g of azobisisobutyronitrile into the reactio...
Embodiment 2
[0075] (1) Esterification reaction:
[0076] Take a 1L three-necked flask, add 215ml of petroleum ether, 76.5g (0.19mol) of cholesterol, 15.03g (0.19mol) of pyridine, and 0.41g of DMAP into the reaction flask, vacuumize and replenish nitrogen, and when the internal temperature rises to 45°C, start adding dropwise Benzoyl chloride 26.7g (0.19mol), the dropwise addition time is controlled at 45min, the temperature is continued to rise to 70°C, and the reaction is kept for 5.5h. After the reaction is completed, add 80ml of water to quench the reaction, wash and extract three times, concentrate the oil layer, add 200ml of acetone to the concentrated substrate, reflux at 70°C for 30min, cool to room temperature, and filter to obtain cholesterol benzoate.
[0077] (2) bromine reaction:
[0078] Put 10g (0.02mol) of cholesterol benzoate obtained in step (1), 2.28g (0.008mol) of DDH, 2.12g (0.02mol) of sodium carbonate, 100ml of n-hexane, and 0.08g of azobisisobutyronitrile into the ...
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