Yield: 83.3%

Reaction Conditions:

Stage #1:2-methoxy-phenylamine with hydrogenchloride;sodium nitrite in water at 0 - 20; for 1 h;
Stage #2: with ammonium hydroxide;sodium hydrogensulfite;sodium chloride in water; pH=6 at 60 - 75; for 1.5 h;
Stage #3: with hydrogenchloride in water; pH=0.14 - 9.1 at 5 - 25; for 3 h;pH-value;Temperature;

Steps:

1
20.14 g (0.16 mol) of o-anisidines, the water 25.12g, and the 20-% by weight chloride 60.77g (0.33 mol) were put into a 300-ml flask, and it stirred at the room temperature, and considered it as the solution. It cooled at 0 degree C, stirring the solution, and the 40-% by weight sodium nitrite aqueous solution 28.49g (0.17 mol) was dropped over 1 hour, keeping the temperature of mixed liquor at 0 degree C, and mixed liquor (i) 134.52g containing o-methoxybenzene chloride diazonium was obtained. When high performance chromatography analyzed the mixed liquor (i), the contained amount of o-methoxybenzene chloride diazonium in mixed liquor (i) was 20.76 % by weight, and the yield of o-methoxybenzene chloride diazonium to o-anisidine was 100%. In a 300ml flask, o- anisidine 20.14g (0.16 mol), water25.12g and 20 wt% hydrochloric acid 60.77g (0.33 mol) were put and stirred atroom temperature and made a solution. The solution was cooled with stirring to0 , and 40% by weight aqueous sodium nitrite solution 28.49g(0.17 mol) was dropped over a period of 1 hourwhile maintaining the temperature of the mixture to 0 , and a liquid mixture (i) 134.52g containing o- methoxybenzenediazonium chloride was obtained. the mixture (i) was analyzed by high performanceliquid chromatography and the content of o- methoxybenzene diazonium chloridein the mixture (i) was 20.76 wt%, and the yield of o- methoxybenzene diazoniumchloride against o- anisidine was 100%.

References:

SUMITOMO CHEMICAL COMPANYLIMITED;ISHIDA, HAJIME;KIKUCHI, YUTA JP5790159, 2015, B2 Location in patent:Paragraph 0042; 0043