Purifying method of N-(3-methoxy-2-methyl benzoyl)-N'-tert-butylhydrazine

Abstract

The invention discloses a purifying method of N-(3-methoxy-2-methyl benzoyl)-N'-tert-butylhydrazine. The purifying method comprises the steps as follows: adding water and acid to reaction product obtained by reaction of 3-methoxy-2-methyl benzoyl chloride and tert-butylhydrazine to carry out acidizing until pH is less than 3; keeping the hydrolysis temperature of 40 to 105 DEG C, and hydrolyzing for 0.5 to 5 hours for hydrolyzing the byproduct; filtering to remove 3-methoxy-2-methyl benzoic acid; adding alkali to the obtained mother liquor to carry out alkalizing; adjusting pH to 7 to 12; and filtering to obtain the high-purity product N-(3-methoxy-2-methyl benzoyl)-N'-tert-butylhydrazine. The purifying method disclosed by the invention is simple in production, and greatly improves the purity of the product; and moreover, the expensive intermediate 3-methoxy-2-methyl benzoic acid can be recycled, so that the producing cost is reduced; and little three wastes are produced during the processing; and the purifying method is beneficial to environmental protection, and is suitable for industrial production.

Description

technical field

[0001] The invention belongs to the technical field of compound preparation, in particular to a method for purifying N-(3-methoxy-2-methylbenzoyl)-N'-tert-butylhydrazine. Background technique

[0002] N-(3-methoxy-2-methylbenzoyl)-N'-tert-butylhydrazine is an intermediate of the pesticide methoxyfenozide, generally composed of 3-methoxy-2-methylbenzene Formyl chloride and tert-butylhydrazine reaction in the system.

[0003] In the prior art, the traditional purification method of N-(3-methoxy-2-methylbenzoyl)-N'-tert-butylhydrazine is to use solvents, such as sherwood oil, ethyl acetate, ethanol, Carry out recrystallization with methanol etc., the purification separation effect of this method is poor, the yield is low, and cost is high, not environmental protection. Contents of the invention

[0004] The object of the present invention is to overcome the defect that exists in the prior art, provide a kind of N-(3-methoxy-2-methylbenzoyl) that is easy to o...

Examples

Embodiment 1

[0022] a. Preparation of crude product:

[0023] In a 300L reactor equipped with a stirring paddle, add 30kg of tert-butylhydrazine hydrochloride and 100L of toluene, stir, cool down, and add 20% liquid caustic soda dropwise at 0°C. After dropping, 10kg of 3-methoxy-2-methylbenzoyl chloride and 20% liquid caustic soda are added dropwise at this temperature. After dropping, stir at room temperature for five hours, then let stand to separate the water layer and remove the organic layer, a white solid was obtained.

[0024] B, the purification of N-(3-methoxy-2-methylbenzoyl)-N'-tert-butylhydrazine:

[0025] In a 300L reactor equipped with a stirring paddle, add 11.8kg of the crude product obtained in step a (containing 85% of compound (I), 10% of compound (II), etc.), add 200L of water, and add concentrated hydrochloric acid dropwise at room temperature When the pH is less than 1, raise the temperature to 100°C, keep it warm for 1 hour, cool down to room temperature, and filte...

Embodiment 2

[0027] In a 300 L reactor equipped with a stirring paddle, add 11.8 kg of the crude product obtained in step a of Example 1, (containing 85% of compound (I), 10% of compound (II), etc.), add 200 L of water, and Concentrated hydrochloric acid was added dropwise until the pH was equal to 2, and the temperature was raised to 100°C, kept for 1 hour, cooled to room temperature, and filtered to obtain 0.7kg of 3-methoxy-2-methylbenzoic acid (purity 98% by HPLC analysis). In the mother liquor, liquid caustic soda is added dropwise to PH10, filters, obtains 10.2kg high-purity N-(3-methoxyl group-2-methylbenzoyl)-N'-tert-butylhydrazine (purity through HPLC analysis is 96 %), the yield is 97.6%.

Embodiment 3

[0029] In a 300 L reactor equipped with a stirring paddle, add 11.8 kg of the crude product obtained in step a of Example 1, (containing 85% of compound (I), 10% of compound (II), etc.), add 200 L of water, and Add concentrated hydrochloric acid dropwise until the pH is less than 1, raise the temperature to 100°C, keep it warm for 0.5 hours, cool down to room temperature, and filter to obtain 0.8kg of 3-methoxy-2-methylbenzoic acid (purity 98% by HPLC analysis). In the mother liquor, liquid caustic soda is added dropwise to PH9, filters, obtains 9.9kg high-purity N-(3-methoxy-2-methylbenzoyl)-N'-tert-butylhydrazine (the HPLC analysis purity is 98 %), the yield is 96.7%.

technical field

[0001] The invention belongs to the technical field of compound preparation, in particular to a method for purifying N-(3-methoxy-2-methylbenzoyl)-N'-tert-butylhydrazine. Background technique

[0002] N-(3-methoxy-2-methylbenzoyl)-N'-tert-butylhydrazine is an intermediate of the pesticide methoxyfenozide, generally composed of 3-methoxy-2-methylbenzene Formyl chloride and tert-butylhydrazine reaction in the system.

[0003] In the prior art, the traditional purification method of N-(3-methoxy-2-methylbenzoyl)-N'-tert-butylhydrazine is to use solvents, such as sherwood oil, ethyl acetate, ethanol, Carry out recrystallization with methanol etc., the purification separation effect of this method is poor, the yield is low, and cost is high, not environmental protection. Contents of the invention

[0004] The object of the present invention is to overcome the defect that exists in the prior art, provide a kind of N-(3-methoxy-2-methylbenzoyl) that is easy to o...

Examples

Embodiment 1

[0022] a. Preparation of crude product:

[0023] In a 300L reactor equipped with a stirring paddle, add 30kg of tert-butylhydrazine hydrochloride and 100L of toluene, stir, cool down, and add 20% liquid caustic soda dropwise at 0°C. After dropping, 10kg of 3-methoxy-2-methylbenzoyl chloride and 20% liquid caustic soda are added dropwise at this temperature. After dropping, stir at room temperature for five hours, then let stand to separate the water layer and remove the organic layer, a white solid was obtained.

[0024] B, the purification of N-(3-methoxy-2-methylbenzoyl)-N'-tert-butylhydrazine:

[0025] In a 300L reactor equipped with a stirring paddle, add 11.8kg of the crude product obtained in step a (containing 85% of compound (I), 10% of compound (II), etc.), add 200L of water, and add concentrated hydrochloric acid dropwise at room temperature When the pH is less than 1, raise the temperature to 100°C, keep it warm for 1 hour, cool down to room temperature, and filte...

Embodiment 2

[0027] In a 300 L reactor equipped with a stirring paddle, add 11.8 kg of the crude product obtained in step a of Example 1, (containing 85% of compound (I), 10% of compound (II), etc.), add 200 L of water, and Concentrated hydrochloric acid was added dropwise until the pH was equal to 2, and the temperature was raised to 100°C, kept for 1 hour, cooled to room temperature, and filtered to obtain 0.7kg of 3-methoxy-2-methylbenzoic acid (purity 98% by HPLC analysis). In the mother liquor, liquid caustic soda is added dropwise to PH10, filters, obtains 10.2kg high-purity N-(3-methoxyl group-2-methylbenzoyl)-N'-tert-butylhydrazine (purity through HPLC analysis is 96 %), the yield is 97.6%.

Embodiment 3

[0029] In a 300 L reactor equipped with a stirring paddle, add 11.8 kg of the crude product obtained in step a of Example 1, (containing 85% of compound (I), 10% of compound (II), etc.), add 200 L of water, and Add concentrated hydrochloric acid dropwise until the pH is less than 1, raise the temperature to 100°C, keep it warm for 0.5 hours, cool down to room temperature, and filter to obtain 0.8kg of 3-methoxy-2-methylbenzoic acid (purity 98% by HPLC analysis). In the mother liquor, liquid caustic soda is added dropwise to PH9, filters, obtains 9.9kg high-purity N-(3-methoxy-2-methylbenzoyl)-N'-tert-butylhydrazine (the HPLC analysis purity is 98 %), the yield is 96.7%.

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