1-naphthylhydrazine preparation method

A technology of naphthalene hydrazine and naphthol, which is applied in the field of preparation of 1-naphthyl hydrazine, can solve the problems of difficulty in guaranteeing purity, low yield, pollution, etc., and achieve the effects of no environmental pollution, high yield, and easy availability of raw materials

Inactive Publication Date: 2006-07-12
FUDAN UNIV
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Problems solved by technology

This method is the main synthetic route used in the current literature, but the disadvantages are: (1) due to the intermediate step of diazotization, the operation requires low temperature conditions and is relatively complicated, the labor protection conditions are poor, and the equipment is severely corroded.
(2) During reduction, especially when iron powder is used for reduction, a large amount of raw materials are wasted and serious environmental pollution is caused
The catalytic reduction principle requires the use of expensive noble metal catalysts, and the use of hydrogen presents safety concerns
(3) The diazotization and reduction process lead to low yield and difficult to guarantee the purity
[0004] Literature (Journal of Organic Chemistry, 1988, 53 (11), 2565-2572.) discloses a method for preparing 1-naphthylhydrazine through a heterocyclic compound containing secondary amine, but this kind of route raw material is difficult to obtain, and production cost is higher , there are difficulties in practical application

Method used

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  • 1-naphthylhydrazine preparation method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0016] Add 25 grams of 1-naphthol (industrial product), 200 grams of hydrazine hydrate aqueous solution (weight concentration is 80%) and 20 grams of sodium bisulfite in a 500 milliliter three-necked flask with stirring and reflux condenser, heat under nitrogen protection React at 120-130° C. for 30 hours, then cool, filter, rinse with deionized water until the pH value is basically constant, and dry the filter cake to obtain 18 grams of white solid 1-naphthylhydrazine with a yield of 67%. Recrystallization from a solution of ethanol / water=2:1 can give crystal 1-naphthylhydrazine.

Embodiment 2

[0018] Add 50 grams of 1-naphthol (industrial product), 400 grams of hydrazine hydrate aqueous solution (50% by weight) and 20 grams of ammonium chloride in a 1000 milliliter three-necked flask with stirring and reflux condenser, and heat to React at 130-140°C for 40 hours, slowly add 200 ml of ice water while stirring, continue stirring for half an hour, filter, wash with water, and dry to obtain 32 g of white solid 1-naphthylhydrazine with a yield of 61%.

Embodiment 3

[0020] Add 50 grams of 1-naphthol (industrial product), 200 grams of hydrazine hydrate aqueous solution (weight concentration is 80%) and 1 gram of molecular sieves in the 1000 milliliters three-neck flasks with stirring and reflux condenser, be heated to 130- React at 140°C for 30 hours, filter molecular sieves, filter after cooling, rinse with deionized water until the pH value is basically constant, and dry the filter cake to obtain 47 grams of white solid 1-naphthylhydrazine with a yield of 87%.

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Abstract

The invention relates to a method for synthesizing 1-naphthalene hydrazine in the field of organic synthesizing technology. The method uses 1-naphthalene hydrazine and hydrazine hydrate as raw material and the inactive gas to protect it to heat stir at normal pressure or pressured condition to obtain the 1-naphthalene hydrazine.

Description

technical field [0001] The invention belongs to the technical field of organic synthesis, and in particular relates to a preparation method of 1-naphthylhydrazine. Background technique [0002] 1-Naphthylhydrazine is a widely used intermediate in organic synthesis, which can be used in the preparation of dyes, medicines and other chemicals. In the existing method for preparing 1-naphthylhydrazine, as Portoghese P.S. etc. report in Journal of Medicinal Chemistry, 1990,33 (6), 1714-1720, mainly adopt following method: [0003] 1-naphthylamine is diazotized with nitrite under acidic conditions, and then reduced to prepare 1-naphthylhydrazine. This kind of method is the synthetic route mainly adopted in the current literature, but the disadvantages are: (1) due to the intermediate step of diazotization, the operation requires low temperature conditions and is relatively complicated, the labor protection conditions are poor, and the equipment is severely corroded. (2) During re...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C241/02C07C243/22
Inventor 余英丰李善君
Owner FUDAN UNIV
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