A kind of preparation method of 3-amino-4-methoxybenzanilide

Abstract

The invention relates to a preparation method of 3-amino-4-methoxybenzaniline.The preparation method includes the steps that 3-nitro-4-X-benzoic acid reacts with aniline under a reaction agent condition to obtain 3-nitro-4-X-benzanilide; 2, 3-nitro-4-X-benzanilide reacts with methyl alcohol under the presence of alkaline reagent to obtain 3-nitro-4 methoxybenzaniline; reduction reaction is performed with treatment or without treatment, so that 3-amino-4-methoxybenzaniline is obtained.The method is high in product yield, low in cost, good in quality and convenient to industrialize and meets the requirement for environmentally-friendly production.

Description

technical field

[0001] The invention relates to a preparation method of fine chemical products, in particular to a preparation method of 3-amino-4-methoxybenzanilide. Background technique

[0002] 3-Amino-4-methoxybenzanilide, also known as red base KD, DB-40, has the structural formula shown in formula I. It is an important fine chemical intermediate and is widely used in the dye industry. Dyeing and printing of cotton, rayon and hemp fibers. In addition, it is also an important intermediate for the synthesis of organic pigments. The types of organic pigments synthesized with this intermediate include: Pigment Red 31, 32, 146, 147, 150, 176, etc. .

[0003] The current main production process of red-based KD is to use o-nitroanisole as a raw material, and it is prepared through chloromethylation, hydrolysis, oxidation, amidation, condensation, and reduction. The reaction route is as follows:

[0004]

[0005] The above route has long steps, low yield, high cost, and ...

Examples

Embodiment 1

[0033] A kind of preparation method of 3-amino-4-methoxybenzanilide, it comprises the steps:

[0034] (1) Preparation of 3-nitro-4-chlorobenzoanilide: In a 1000L reaction vessel, pump chlorobenzene (200kg), start stirring, and add 3-nitro-4-chlorobenzoic acid (50kg , percent), aniline (27kg), warm up to 70-80°C, add phosphorus trichloride (20kg) dropwise, after the dropwise addition, heat up to 100°C, keep warm for 2 hours, drop to room temperature, add water (400kg) dropwise , heating up to reflux, changing the reflux to distillation, steaming chlorobenzene at normal pressure, cooling, filtering, and drying to obtain 65.7kg of 3-nitro-4-chlorobenzanilide, which is a yellow-brown solid with a purity of 98.1%. The yield is 95.8%, and the melting point is 128-130°C;

[0035] (2) Preparation of 3-nitro-4-methoxybenzanilide: In a 1000L reaction vessel, draw methanol (400kg), start stirring, add 3-nitro-4-chlorobenzanilide ( 55.4kg), sodium methoxide (11.9kg), start stirring, hea...

Embodiment 2

[0038] This example provides a kind of synthetic method of 3-amino-4-methoxybenzanilide, and it comprises the steps:

[0039] (1) Preparation of 3-nitro-4-chlorobenzanilide: In a 1000L reaction vessel, pump chlorobenzene (200kg) and aniline (27kg), start stirring, and add 3-nitro-4-chlorobenzene Formic acid (50kg, 100%), heat up to 70-80°C, add thionyl chloride (40kg) dropwise, after the dropwise addition, heat up to 100°C, keep warm for 2 hours, drop to room temperature, add water (400kg) dropwise, heat up To reflux, change the reflux to distillation, steam chlorobenzene at normal pressure, cool down, filter, and dry to obtain 66.5kg of 3-nitro-4-chlorobenzanilide, which is a yellow-brown solid with a purity of 98.5%. It is 97%, and its melting point is 128-130°C;

[0040](2) Preparation of 3-nitro-4-methoxybenzanilide: In a 1000mL reaction vessel, draw methanol (400kg), start stirring, add 3-nitro-4-chlorobenzanilide ( 55.4kg), potassium hydroxide (12.3kg), heated to reflu...

Embodiment 3

[0043] This example provides a kind of synthetic method of 3-amino-4-methoxybenzanilide, and it comprises the steps:

[0044] (1) Preparation of 3-nitro-4-chlorobenzanilide: In a 1000L reaction vessel, add 3-nitro-4-chlorobenzoic acid (50kg, percent), dichlorobenzene (300kg), aniline (30kg), triphenyl phosphite (5kg), heat up to 115°C to reflux, toluene brings out water during reflux, after reflux for 6-7 hours, cool down, filter, and dry to obtain 3-nitro-4- 60.5kg of chlorobenzanilide is a yellow-brown solid with a purity of 98.0%, a yield of 88.2%, and a melting point of 128-130°C. Toluene mother liquor (containing catalyst) is recovered and applied mechanically;

[0045] (2) Preparation of 3-nitro-4-methoxybenzanilide: In a 1000L reaction flask, draw methanol (400kg), start stirring, add 3-nitro-4-chlorobenzanilide ( 55.4kg), sodium hydroxide (8.8kg), heated and refluxed for 8 hours, cooled, filtered, washed with water, and dried to obtain 51.9kg of 3-nitro-4-methoxybenz...

technical field

[0001] The invention relates to a preparation method of fine chemical products, in particular to a preparation method of 3-amino-4-methoxybenzanilide. Background technique

[0002] 3-Amino-4-methoxybenzanilide, also known as red base KD, DB-40, has the structural formula shown in formula I. It is an important fine chemical intermediate and is widely used in the dye industry. Dyeing and printing of cotton, rayon and hemp fibers. In addition, it is also an important intermediate for the synthesis of organic pigments. The types of organic pigments synthesized with this intermediate include: Pigment Red 31, 32, 146, 147, 150, 176, etc. .

[0003] The current main production process of red-based KD is to use o-nitroanisole as a raw material, and it is prepared through chloromethylation, hydrolysis, oxidation, amidation, condensation, and reduction. The reaction route is as follows:

[0004]

[0005] The above route has long steps, low yield, high cost, and ...

Examples

Embodiment 1

[0033] A kind of preparation method of 3-amino-4-methoxybenzanilide, it comprises the steps:

[0034] (1) Preparation of 3-nitro-4-chlorobenzoanilide: In a 1000L reaction vessel, pump chlorobenzene (200kg), start stirring, and add 3-nitro-4-chlorobenzoic acid (50kg , percent), aniline (27kg), warm up to 70-80°C, add phosphorus trichloride (20kg) dropwise, after the dropwise addition, heat up to 100°C, keep warm for 2 hours, drop to room temperature, add water (400kg) dropwise , heating up to reflux, changing the reflux to distillation, steaming chlorobenzene at normal pressure, cooling, filtering, and drying to obtain 65.7kg of 3-nitro-4-chlorobenzanilide, which is a yellow-brown solid with a purity of 98.1%. The yield is 95.8%, and the melting point is 128-130°C;

[0035] (2) Preparation of 3-nitro-4-methoxybenzanilide: In a 1000L reaction vessel, draw methanol (400kg), start stirring, add 3-nitro-4-chlorobenzanilide ( 55.4kg), sodium methoxide (11.9kg), start stirring, hea...

Embodiment 2

[0038] This example provides a kind of synthetic method of 3-amino-4-methoxybenzanilide, and it comprises the steps:

[0039] (1) Preparation of 3-nitro-4-chlorobenzanilide: In a 1000L reaction vessel, pump chlorobenzene (200kg) and aniline (27kg), start stirring, and add 3-nitro-4-chlorobenzene Formic acid (50kg, 100%), heat up to 70-80°C, add thionyl chloride (40kg) dropwise, after the dropwise addition, heat up to 100°C, keep warm for 2 hours, drop to room temperature, add water (400kg) dropwise, heat up To reflux, change the reflux to distillation, steam chlorobenzene at normal pressure, cool down, filter, and dry to obtain 66.5kg of 3-nitro-4-chlorobenzanilide, which is a yellow-brown solid with a purity of 98.5%. It is 97%, and its melting point is 128-130°C;

[0040](2) Preparation of 3-nitro-4-methoxybenzanilide: In a 1000mL reaction vessel, draw methanol (400kg), start stirring, add 3-nitro-4-chlorobenzanilide ( 55.4kg), potassium hydroxide (12.3kg), heated to reflu...

Embodiment 3

[0043] This example provides a kind of synthetic method of 3-amino-4-methoxybenzanilide, and it comprises the steps:

[0044] (1) Preparation of 3-nitro-4-chlorobenzanilide: In a 1000L reaction vessel, add 3-nitro-4-chlorobenzoic acid (50kg, percent), dichlorobenzene (300kg), aniline (30kg), triphenyl phosphite (5kg), heat up to 115°C to reflux, toluene brings out water during reflux, after reflux for 6-7 hours, cool down, filter, and dry to obtain 3-nitro-4- 60.5kg of chlorobenzanilide is a yellow-brown solid with a purity of 98.0%, a yield of 88.2%, and a melting point of 128-130°C. Toluene mother liquor (containing catalyst) is recovered and applied mechanically;

[0045] (2) Preparation of 3-nitro-4-methoxybenzanilide: In a 1000L reaction flask, draw methanol (400kg), start stirring, add 3-nitro-4-chlorobenzanilide ( 55.4kg), sodium hydroxide (8.8kg), heated and refluxed for 8 hours, cooled, filtered, washed with water, and dried to obtain 51.9kg of 3-nitro-4-methoxybenz...

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