A kind of preparation method of ultraviolet absorber uv-328
A technology of UV-328 and absorbent, applied in the field of preparation of UV absorbent UV-328, can solve the problems of high cost, environmental pollution, low yield and the like
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Embodiment 1
[0032] The invention prepares 2-(2'-hydroxyl-3',5'-di-t-pentylphenyl from o-nitrochlorobenzene through ammoniation, diazotization, coupling, one-step reduction, two-step reduction reaction and post-treatment process ) Benzotriazole products.
[0033] Step 1, the preparation of 2-nitroaniline: put 1mol of 2-nitrochlorobenzene and 20mol of 20% ammonia water into the pipeline type ammoniation reactor and perform the ammoniation reaction at 150~220°C and 12~20MPa for 30~ After 50 minutes, the residual ammonia in the system was sprayed to circulate and absorb the low-concentration ammonia water produced, and after adding part of the liquid ammonia, it continued to be used for the ammonification reaction. neutralize and recover ammonia in water), and obtain 2-nitroaniline product through cooling and crystallization, with a yield of ≥98.6% and a purity of ≥99.6%.
[0034] Step 2. Preparation of 2-nitrodiazophenyl hydrochloride: Add 1mol of 2-nitroaniline, 3.2mol of 31% hydrochloric ...
Embodiment 2
[0039] The invention prepares 2-(2'-hydroxyl-3',5'-di-t-pentylphenyl from o-nitrochlorobenzene through ammoniation, diazotization, coupling, one-step reduction, two-step reduction reaction and post-treatment process ) Benzotriazole products.
[0040] Step 1. Preparation of 2-nitroaniline: put 1mol of 2-nitrochlorobenzene and 22mol of 10% ammonia water into the pipeline ammoniation reactor, and perform ammoniation reaction at 150~220°C and 12~20MPa for 30~ After 50 minutes, the residual ammonia in the system was sprayed to circulate and absorb the low-concentration ammonia water produced, and after adding part of the liquid ammonia, it continued to be used for the ammonification reaction. neutralize and recover ammonia in water), and obtain 2-nitroaniline product through cooling and crystallization, with a yield of ≥98.3% and a purity of ≥99.2%.
[0041] Step 2. Preparation of 2-nitrodiazophenyl hydrochloride: Add 1 mol of 2-nitroaniline, 3 mol of 5% hydrochloric acid and 500 ...
Embodiment 3
[0046] The invention prepares 2-(2'-hydroxyl-3',5'-di-t-pentylphenyl from o-nitrochlorobenzene through ammoniation, diazotization, coupling, one-step reduction, two-step reduction reaction and post-treatment process ) Benzotriazole products.
[0047] Step 1. Preparation of 2-nitroaniline: put 1mol of 2-nitrochlorobenzene and 12mol of 25% ammonia water into a pipeline ammoniation reactor and perform ammoniation reaction at 150-220°C and 12-20MPa for 30- After 50 minutes, the residual ammonia in the system was sprayed to circulate and absorb the low-concentration ammonia water produced, and after adding part of the liquid ammonia, it continued to be used for the ammonification reaction. neutralize and recover ammonia in water), and obtain 2-nitroaniline product through cooling and crystallization, with a yield of ≥98.2% and a purity of ≥99.5%.
[0048] Step 2, preparation of 2-nitrodiazophenyl hydrochloride: add 1mol of 2-nitroaniline, 4mol of 35% hydrochloric acid and 500ml of...
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