Chemical synthesizing method for 5-chlorine-2-nitroaniline

Abstract

The method for synthesizing 5-chloro-2-nitrophenylamine uses 3-chlorophenylamine as initial raw material, and utilizes three-step reaction of formylation, nitration and hydrolysis to synthesize object compound 5-chloro-2-nitrophenylamine, its total yield rate is above 60% and its product purity is above 98%.

Description

Technical field:

[0001] The present invention relates to a new method for synthesizing 5-chloro-2-nitroaniline. The method uses 3-chloroaniline as a starting material to synthesize target compound 5-chloro-2-nitroaniline through three steps of formylation, nitration and hydrolysis. Background technique:

[0002] 5-Chloro-2-nitroaniline is an important pharmaceutical and pesticide intermediate. The method for the preparation of 5-chloro-2-nitroaniline reported in the literature is to take 3-chloroaniline as starting material, first reacts with acetic anhydride to prepare 3-chloroacetanilide, then in the mixed solvent of acetic acid and acetic anhydride, use Nitration with fuming nitric acid produced 5-chloro-2-nitroacetanilide, and finally reflux reaction in sodium methoxide / methanol solution for 24 hours to synthesize the target compound 5-chloro-2-nitroacetaniline (GB2018766). This method uses acetic anhydride as a protecting group, and the cost is relatively high; when 3...

Examples

Embodiment 1

[0016] 3-Chloroformanilide: In a 250ml three-necked flask equipped with a water separator, add 51.5g (0.41mol) 3-chloroaniline and 150ml toluene, stir to dissolve, then slowly add 23.5g (0.45mol) 88% formic acid , heat up and reflux for 1h, cool to 65-70°C, add 6.4g (0.12mol) 88% formic acid, heat up and reflux again for 1h, cool to room temperature, remove toluene and excess formic acid on a rotary evaporator, cool to obtain white Solid 3-chloroformanilide 61.7g, yield 97%, m.p.51~53℃.

Embodiment 2

[0018] 3-Chloroformanilide: except that benzene was used instead of toluene, other operating conditions were the same as in Example 1 to obtain 53.8 g of 3-chloroformanilide as a white solid with a yield of 84%, m.p.50-53°C.

Embodiment 3

[0020] 3-Chloroformanilide: except that n-butyl ether was used instead of toluene, other operating conditions were the same as in Example 1 to obtain 58.2 g of 3-chloroformanilide as a white solid, yield 91%, m.p.51-53°C.

Technical field:

[0001] The present invention relates to a new method for synthesizing 5-chloro-2-nitroaniline. The method uses 3-chloroaniline as a starting material to synthesize target compound 5-chloro-2-nitroaniline through three steps of formylation, nitration and hydrolysis. Background technique:

[0002] 5-Chloro-2-nitroaniline is an important pharmaceutical and pesticide intermediate. The method for the preparation of 5-chloro-2-nitroaniline reported in the literature is to take 3-chloroaniline as starting material, first reacts with acetic anhydride to prepare 3-chloroacetanilide, then in the mixed solvent of acetic acid and acetic anhydride, use Nitration with fuming nitric acid produced 5-chloro-2-nitroacetanilide, and finally reflux reaction in sodium methoxide / methanol solution for 24 hours to synthesize the target compound 5-chloro-2-nitroacetaniline (GB2018766). This method uses acetic anhydride as a protecting group, and the cost is relatively high; when 3...

Examples

Embodiment 1

[0016] 3-Chloroformanilide: In a 250ml three-necked flask equipped with a water separator, add 51.5g (0.41mol) 3-chloroaniline and 150ml toluene, stir to dissolve, then slowly add 23.5g (0.45mol) 88% formic acid , heat up and reflux for 1h, cool to 65-70°C, add 6.4g (0.12mol) 88% formic acid, heat up and reflux again for 1h, cool to room temperature, remove toluene and excess formic acid on a rotary evaporator, cool to obtain white Solid 3-chloroformanilide 61.7g, yield 97%, m.p.51~53℃.

Embodiment 2

[0018] 3-Chloroformanilide: except that benzene was used instead of toluene, other operating conditions were the same as in Example 1 to obtain 53.8 g of 3-chloroformanilide as a white solid with a yield of 84%, m.p.50-53°C.

Embodiment 3

[0020] 3-Chloroformanilide: except that n-butyl ether was used instead of toluene, other operating conditions were the same as in Example 1 to obtain 58.2 g of 3-chloroformanilide as a white solid, yield 91%, m.p.51-53°C.

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