成人免费xx,国产又黄又湿又刺激不卡网站,成人性视频app菠萝网站,色天天天天

Welcome to chemicalbook!
Chinese English Japanese Germany Korea
400-158-6606
Try our best to find the right business for you.
Do not miss inquiry messages Please log in to view all inquiry messages.

Welcome back!

ChemicalBook CAS DataBase List Minoxidil
38304-91-5

Minoxidil synthesis

3synthesis methods
Minoxidil, 6-amino-1,2-dihydro-1-hydroxy-2-imino-4-piperidinopyrimidine (22.8.5), is synthesized from barbituric acid, the reaction of which with phosphorous oxychloride gives 2,4,6-trichloropyrimidine (22.8.1). Upon reaction with ammonium, this turns into 2,4-diamino-6-chloropyrimidine (22.8.2). Next, the resulting 2,4-diamino-6- chloropyrimidine (22.8.2) undergoes reaction with 2,4-dichlorophenol in the presence of potassium hydroxide, giving 2,4-diamino-6-(2,4-dichlorophenoxy)-pyrimidine (22.8.3). Oxidation of this product with 3-chloroperbenzoic acid gives 2,4-diamino-6-(2,4- dichlorophenoxy)pyrimidine-3-oxide (22.8.4), the 2,4-dichlorophenoxyl group of which is replaced with a piperidine group at high temperature, giving minoxidil (22.8.5).

-

Yield:38304-91-5 86.2%

Reaction Conditions:

at 103; for 4 h;Large scale;Concentration;

Steps:

1.B; 1.C; 2.B; 2.C B. Synthesis of Crude Minoxidil

13.08mol of 2,4-diamino-6-chloropyrimidine-1-oxide and 18.06kg of piperidine were added to the double-layer glass reaction kettle, the temperature was raised to 103°C with stirring, and the reaction was refluxed for 4 hours. The reaction end was monitored by TLC chromatographic plate.After the reaction was completed, the temperature was lowered to 5°C with stirring, overnight crystallization, suction filtration, the filter cake was washed with piperidine once, and dried to obtain 2.74 kg of off-white solid minoxidil crude product, the product purity was 97.39%, and the yield was 100%. .C. Synthesis of Minoxidil2.6kg of the minoxidil crude product, 6.1kg of isopropanol and 7.8kg of purified water were added to the double-layer glass reaction kettle, and the temperature was raised to 76°C with stirring, and the reflux reaction was performed for 1 hour to make the system clear; the temperature was lowered to 5°C with stirring, Crystallization overnight, suction filtration, the filter cake was washed once with isopropanol, and dried to obtain 2.24 kg of off-white solid minoxidil, the product purity was 100%, and the yield was 86.2%.

References:

CN113979952,2022,A Location in patent:Paragraph 0040; 0043-0046; 0049; 0052-0055

Minoxidil Related Search: