New preparation method of 5-nitro-salicylaldehyde

A technology of nitrosalicylaldehyde and salicylaldehyde, which is applied in the preparation of nitro compounds and organic chemistry, and can solve problems such as unfavorable large-scale production of 5-nitrosalicylaldehyde, difficulty in separation and purification, and low reaction rate , to achieve the effect of facilitating large-scale synthesis, increasing the reaction rate, and increasing the yield

CN102633646BInactive Publication Date: 2014-06-04OCEAN UNIV OF CHINA
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2014-06-04
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention belongs to the technical field of preparation of chemical intermediates needed by the synthetic process of medicine, dye, pesticide, spice and the like, and particularly relates to a method for preparing 5-nitro-salicylaldehyde by an improved low-temperature nitration method, which takes salicylaldehyde as a raw material; and the 5-nitro-salicylaldehyde is prepared by the improved low-temperature nitration method. In the reaction process, a brand new ternary mixed solvent system consisting of hydrofluoric acid, acetic anhydride and acetic acid is adopted, so that the reaction speed of low-temperature nitration and the yield of the 5-nitro-salicylaldehyde synthesized by the nitration method can be successfully improved. The synthesis conditions of the method can be easily controlled, so that the method is especially suitable for preparing the 5-nitro-salicylaldehyde in a laboratory; and meanwhile, the raw materials are easily obtained, and the production cost is comparatively low, so that the method has certain implementation value and socio-economic benefit.
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Description

technical field

[0001] The invention belongs to the technical field of preparation of chemical intermediates in the synthesis process of medicines, dyes, pesticides and spices, and specifically relates to an improved method for preparing 5-nitrosalicylaldehyde through low-temperature nitration. Background technique

[0002] 5-Nitrosalicylaldehyde is a chemical intermediate widely used in the synthesis of medicines, dyes, pesticides and spices. In the development and utilization of drugs, Dronedarone hydrochloride synthesized from 5-nitrosalicylaldehyde has a chemical name of 2-n-butyl-3-[4-(3-di-n-butylamino Propoxy)benzoyl]-5-methanesulfonamidobenzofuran is an important drug for the treatment of cardiovascular diseases; in the synthesis of marine drug chitosan, the hydroxyl group prepared by 5-nitrosalicylaldehyde The antibacterial effect and antioxidant capacity of propyl chitosan Schiff base are significantly higher than those of hydroxypropyl chitosan Schiff base prepar...

Examples

Embodiment 1

[0022] Measure 100ml of glacial acetic acid, 12.5g of hydrofluoric acid, 25.9g of acetic anhydride, and 25.7g of salicylaldehyde into a 250ml three-neck flask in turn, and keep stirring in an ice-water bath to cool below 5°C. Put 16.6g of fuming nitric acid in a constant pressure dropping funnel, control the temperature within the range of 5-10°C, and evenly drop the fuming nitric acid into the three-necked flask within 2.5 hours. Then control the temperature at 8-10°C to react for 1 hour, then raise the temperature to 15-20°C to continue the reaction for 1 hour. While hot, pour the reaction solution into a mixture of 500 g of crushed ice and water, stir evenly, and let stand for 5 hours (or stand overnight). Suction filtration, washing and drying gave 28.3 g of yellow powder solid. After water extraction, 14.8 g of light yellow 5-nitrosalicylaldehyde powder was obtained with a yield of 52%.

[0023] Infrared spectrum (KBr, cm -1 ): 3069cm -1 ;2883cm -1 ;1664cm -1 ;1625,...

Embodiment 2

[0026] Measure 100ml of glacial acetic acid, 12.5g of hydrofluoric acid, 25.9g of acetic anhydride, and 25.7g of salicylaldehyde into a 250ml three-neck flask in turn, and keep stirring in an ice-water bath to cool below 5°C. Put 16.6g of fuming nitric acid in a constant pressure dropping funnel, control the temperature in the range of 5 to 102, and evenly drop the fuming nitric acid into the three-necked flask within 2.5 hours. Then control the temperature at 8-10°C to react for 1 hour, then raise the temperature to 15-20°C to continue the reaction for 1 hour. While hot, pour the reaction solution into 500g of crushed ice and water mixture, stir evenly, and let stand for 5h (or stand overnight). Suction filtration, washing and drying gave 25.5 g of yellow powder solid. After water extraction, 12.7 g of light yellow 5-nitrosalicylaldehyde powder was obtained with a yield of 50%.

[0027] Infrared spectrum (KBr, cm -1 ): 3070cm -1 ;2885cm -1 ;1657cm -1 ;1614, 1578, 1447cm...

Embodiment 3

[0030] Measure 100ml of glacial acetic acid, 5.0g of hydrofluoric acid, 25.9g of acetic anhydride, and 25.7g of salicylaldehyde into a 250ml three-neck flask in turn, and keep stirring in an ice-water bath to cool below 5°C. Put 16.6g of fuming nitric acid in a constant pressure dropping funnel, control the temperature within the range of 5-10°C, and evenly drop the fuming nitric acid into the three-necked flask within 2.5 hours. Then control the temperature at 8-10°C to react for 1 hour, then raise the temperature to 15-20°C to continue the reaction for 1 hour. While hot, pour the reaction solution into 500g of crushed ice and water mixture, stir evenly, and let stand for 5h (or stand overnight). Suction filtration, washing and drying gave 32.0 g of yellow powder solid. After water extraction, 12.6 g of light yellow 5-nitrosalicylaldehyde powder was obtained with a yield of 39%. The reason for the substantial reduction in the yield of this synthesis is that the amount of hy...