天堂网亚洲,天天操天天搞,91视频高清,菠萝蜜视频在线观看入口,美女视频性感美女视频,95丝袜美女视频国产,超高清美女视频图片

Welcome to chemicalbook!
Chinese English Japanese Germany Korea
010-86108875
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 ANTIPYRINECARBOXYLIC ACID
83-10-3

ANTIPYRINECARBOXYLIC ACID synthesis

12synthesis methods
4-ANTIPYRINECARBOXALDEHYDE

950-81-2

ANTIPYRINECARBOXYLIC ACID

83-10-3

The general procedure for the synthesis of 1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazole-4-carboxylic acid from 4-antipyrinecarboxaldehyde is as follows: 1. 1-benzyl-5-methyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazole-4-carboxaldehyde (1 g, 4.624 mmol) was dissolved in butanol at 0 °C to prepare a mixture. 2. An aqueous solution of NaClO2 (1.254 g, 13.873 mmol) and an aqueous solution of potassium dihydrogen phosphate monohydrate (3.146 g, 23.12 mmol) were slowly added to the above mixture. 3. the reaction mixture was slowly heated to room temperature with continuous stirring for 10 hours. 4. During the reaction, NaClO3 (1 g) was further added and the progress of the reaction was monitored. 5. After addition of sodium chlorite, stirring of the reaction mixture was continued followed by extraction with ethyl acetate. 6. The organic layer was washed, dried with Na2SO4 and filtered. 7. The filtrate was concentrated under reduced pressure to give a residue. 8. The residue was washed with hexane solution of 20% ethyl acetate to afford the target compound 1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazole-4-carboxylic acid as a white solid (808 mg, 3.48 mmol, 75% yield). Product characterization data: 1H NMR (400 MHz, DMSO): δ 12.22 (br s, 1H), 7.61-7.42 (m, 5H), 3.36 (s, 3H), 2.59 (s, 3H).

-

Yield:-

Steps:

Multi-step reaction with 2 steps
1: CS2; AlCl3 / anschliessend mit H2O
2: aqueous H2O2

References:

Schmidt [Archiv der Pharmazie,1956,vol. 289,p. 150,154]

ANTIPYRINECARBOXYLIC ACID Related Search: