methyl N-ethyl-N-[4-[(5-nitro-2,1-benzisothiazol-3-yl)azo]phenyl]-beta-alaninate synthesis

Yield:52239-04-0 94.3 %

Reaction Conditions:

Stage #1: 3-amino-5-nitrobenzisothiazolewith sulfuric acid at 60;
Stage #2: with nitrosylsulfuric acid in water at 35 - 40;
Stage #3: N-ethyl-N'-2-(methoxycarbonyl)ethylanilineFurther stages;

Steps:

1 Step 1, diazotization: a1

Add 678kg of sulfuric acid into the diazo pot, and add 300kg of diazo component 3-amino-5-nitrobenzisothiazole under stirring at no more than 60°C, and the addition time is 1.5h; keep stirring for 5min after adding, then use 30kg of sulfuric acid to clean the surrounding powder, and slowly raise the temperature and stir to 60°C, keep warm for 2h until it dissolves; a2, use circulating water to cool down to 35°C, and add 525kg of nitrous sulfuric acid under the condition of 35-40°C, and complete the addition within 50 minutes; then continue to cool down to 0°C after the addition is completed, and Add 81kg of propionic acid at 5°C, keep warm for 2 hours after adding, and feed back once during the hold; a4, at 0±2°C, add 156kg of crushed ice evenly, adding time is 1h, after adding, 0-2 Insulate at for 1h, and discharge to obtain diazonium salt;Step 2, coupling: b1, add 3000kg of bottom water, 2100kg of ice, 135kg of ice, 30kg of dispersant X-10, 270kg of acetic acid in the coupling pot, and keep at 0°C, add 366kg of coupling component N-ethyl - N-phenyl-β-alanine methyl ester, stirred for 15 minutes, then added 30kg of sulfamic acid and 7kg of defoamer in turn, and stirred for 5 minutes after the addition, to obtain the coupling solution; b2, through the distributor in multiple steps Add diazonium salt for the first time, specifically divided into five additions of diazonium salt, including: for the first time, add 360kg of diazonium salt for 5 minutes, add 825kg of sodium acetate for 3 minutes after the addition, and add 450kg of water, and stir for 1 minute; Add 360kg diazonium salt for the first time, add 666kg sodium acetate quickly after adding, and add 1050kg ice, stir for 1min; add 360kg diazonium salt for the third time, add 666kg sodium acetate quickly after adding, and add 2250kg ice, 450kg water, and keep stirring at 0°C for 1 min; add 360kg of diazonium salt for the fourth time, add 636kg of sodium acetate after the addition, and add 1050kg of distilled water, stir for 1min, add the remaining diazonium salt for the fifth time, and after the addition is completed Add 1800kg of alkaline aqueous solution within 10 minutes, wherein the alkaline aqueous solution is composed of 600kg of 30% sodium hydroxide solution and 1200kg of water, adjust the pH to 2-3, stir for 30 minutes and then add 80°C hot water to raise the temperature to 20-30°C. After keeping the reaction for 3h, press material to obtain filter cake;Step 3, refining: add 3700kg of water into the coupling refining pot, and add the filter cake for beating for 3 hours, add 18000kg of water after the tape is completely dispersed, and adjust the pH to 4-4.5, heat up to 40°C and press the material to obtain the filter cake;Step 4, press filtration: add the filter cake in step 3 into a 250-type filter press, wash with water for 1 hour, and blow off the material to obtain a crude product; then put the crude product into a 250-type filter press, using 45-60 Wash with hot water at until neutral, blow it until there is no dripping water, and unload to obtain Disperse Blue 148. The yield table of the disperse blue 148 prepared in this embodiment is 94.3%.Put the above dye into water to form a solution of 0.25g/L, then when the pH is 4-4.5, take 100mL and soak 2.5g of polyester fiber for dyeing, heat up from room temperature to 130°C in 40 minutes, keep it warm for 40 minutes, and cool to 60°C, start sampling, then wash, rinse and dry to obtain dyed fabric. According to the standard test, the coloring rate of the dye is 99.78%, the water resistance reaches 5, and the rubbing and sweat fastnesses reach 4-5.

References:

CN115044226,2022,A Location in patent:Paragraph 0020-0026