Pigment Red 4 synthesis
- Product Name:Pigment Red 4
- CAS Number:2814-77-9
- Molecular formula:C16H10ClN3O3
- Molecular Weight:327.72
Yield: 99%
Reaction Conditions:
Stage #1:2-Chloro-4-nitroaniline with hydrogenchloride;sodium nitrite in water at 20; for 0.333333 h;
Stage #2:β-naphthol in water at 20; for 0.666667 h;
Steps:
23 A method for synthesizing C.I. Pigment Red 4 by one-pot method promoted by solid particles, the steps are as follows:
10 g of polytetrafluoroethylene particles (about 70 mg/particle), 2.107 g (3 molar equivalents) of hydrochloric acid (36%), 1.317 g (1.1 molar equivalent) of o-chloro-p-nitroaniline, 0.550 g (1.15 mol) were added to the reaction vessel. Equivalent) sodium nitrite, 5mL water, when stirred with a modified mechanical stirring paddle for 20 minutes at room temperature, the complete conversion of o-chloro-p-nitroaniline was detected by thin-plate chromatography, and 1.000 g (1 molar equivalent) of 2-naphthol was added at room temperature. Continue to stir. After reacting for 40 minutes, the reaction was completed by thin-plate chromatography, filtered and rinsed with 2 mL of water, and the filter cake was dried to obtain 2.280 g of C.I. Pigment Red 4.The reaction mother liquor and rinse solution are reserved for the next cycle. The product yield is greater than 99%.
References:
Tianjin University;Li Chunbao;Feng Guangyuan CN108912723, 2018, A Location in patent:Paragraph 0115; 0116; 0117