36422-63-6

Upstream product

• 1533-44-4 C₂₈H₂₂N₂O₄ 
• 835-71-2 2-(4-methylphenyl)-1,3-benzoxazole 
• 52238-17-2 4,4'-stilbenedicarbonyl dichloride 
• 100-31-2 Stilbene-4,4'-dicarboxylic acid 
• 24239-07-4 2-(4-bromomethylphenyl)benzoxazole 

Relevant academic research and scientific papers

Production process of fluorescent whitening agent OB-1

The invention relates to a production process of a fluorescent whitening agent OB-1. The production process specifically comprises the following steps: 1, carrying out condensation reaction on p-toluic acid and o-aminophenol to generate 4-methyl phenyl benzoxazole; 2, carrying out distillation treatment after the condensation reaction is finished, and collecting a main fraction 4-methyl intermediate; 3, adding methanol into the main fraction, keeping the temperature at 60 DEG C for 6 hours, cooling to 10 DEG C, centrifugally filtering, drying, and transferring into a vulcanization synthesis kettle; 4, carrying out a vulcanization synthesis reaction on the 4-methyl intermediate to generate OB-1, rinsing with xylene, repeatedly washing with xylene, and drying the xylene by distillation to obtain a dried OB-1 crude product; 5, adding trichlorobenzene, the OB-1 crude product and activated carbon into a refining kettle to refine OB-1; and 6, pulping and washing OB-1 with methanol, carryingout centrifugal separation, and drying a filtering cake to obtain the OB-1 product. The method is environmentally friendly, safe and high in yield.

Preparation 2, the 2 [...] -(4,4 the- [...]benzoin ethenyl ) method of the double-benzoxazole

The invention discloses a method for preparing a 2, 2'-(4,4'-distyrylphenyl) phenylene benzobisoxazole competitive product. The method comprises the steps of condensation reaction, sulfurization reaction, refining, solid-liquid separation and the like. In the refining step of a crude product, the crude product is refined and desulphurized under the effect of 30% NaOH solution, the desulphurization rate is high, the purity of the product OB-1 can reach 99 percent, the yield is high, the quality is good, the color is bright, and the application performance is greatly improved; after the traditional dimethylbenzene is substituted by 30% NaOH solution to be used as the desulphurization washing agent, the production safety coefficient is high, safety in operation is realized, and the cost is low. The method can be used for preparing fluorescent whitening agent OB-1 which is used as an auxiliary material for the materials such as plastics, paint, road line paint and the like.

Synthesis and spectral-luminescence properties of 4,4′-di(2-oxazolyl)-stilbenes and 4,4′-di(2-oxazolyl)tolans

A new method is proposed for the synthesis of 4,4′-di(2-oxazolyl)stilbenes and 4,4′-di(2-oxazolyl) tolans by condensation of oxazolyl-substituted benzyl bromides or benzal dibromides under the influence of strong bases (KOH, potassium tertbutoxide) in dipolar aprotic solvents [dimethylformamide (DMF) and dimethyl sulfoxide (DMSO)]. The synthesized compounds luminesce intensely over the spectral range 386-492 nm.

Eine einfache Methode zur Herstellung von Benzoxazolen

The preparation of benzoxazoles by a facile one-pot reaction is reported.The reaction of carboxylic acids with 2-chloro-N-methyl-Δ1-pyrrolinium chloride in an excess of N-methyl-2-pyrrolidone afforded carboxylic acid chlorides which were converted subsequently to their 2-hydroxyanilides by addition of 2-aminophenols.Cyclization of the 2-hydroxy-anilides at elevated temperatures furnished the benzoxazoles in high yield and purity.