A kind of 2-sulfydryl-5-methyl isophthalic acid, the preparation method of 3,4-thiadiazoles
Technical field
The present invention relates to medicine, chemical technology field, a kind of 2-sulfydryl-5-methyl isophthalic acid particularly, the preparation method of 3,4-thiadiazoles.
Background technology
2-sulfydryl-5-methyl isophthalic acid, 3,4-thiadiazoles is a kind of white crystalline powder, is the important intermediate of synthetic antibiotic medicine cephazolin sodium, has important industry and medical value.
Existing 2-sulfydryl-5-methyl isophthalic acid, 3, it is raw material that the preparation method of 4-thiadiazoles mainly adopts hydrazine hydrate, ethyl acetate, methyl alcohol or alcohol solvent, alkali lye, dithiocarbonic anhydride, acid solution, wherein, solvent adopts methyl alcohol or ethanol, alkali lye adopts potassium hydroxide or liquefied ammonia, and acid solution adopts the vitriol oil or concentrated hydrochloric acid, is got through hydrazine, addition, cyclization, hydrolysis by ethyl acetate.Existing 2-sulfydryl-5-methyl isophthalic acid, the preparation method of 3,4-thiadiazoles exists long reaction time, power consumption is large, and complicated operation is loaded down with trivial details, and production cost is high, easily produces simultaneously the weak point of more waste and pollutent.
Summary of the invention
The object of the invention is to for existing 2-sulfydryl-5-methyl isophthalic acid, 3, the existing long reaction time of the preparation method of 4-thiadiazoles, power consumption are greatly, complicated operation is loaded down with trivial details, production cost is high, easily produces simultaneously the weak point of more waste and pollutent, provides that a kind of technological operation is easy, the reaction times is short, production cost is low, waste and pollutent produce few 2-sulfydryl-5-methyl isophthalic acid, the preparation method of 3,4-thiadiazoles.
Technical scheme of the present invention realizes in the following way: a kind of 2-sulfydryl-5-methyl isophthalic acid, and the preparation method of 3,4-thiadiazoles, this 2-sulfydryl-5-methyl isophthalic acid, the preparation method of 3,4-thiadiazoles may further comprise the steps:
⑴ put into reaction vessel with the hydrazine hydrate that takes by weighing and ammoniacal liquor and mix, and drips dithiocarbonic anhydride under the condition that is lower than 5 ℃ of temperature, dropwises rear stirring insulation 0.5~1h, obtains the aqueous solution of diazanyl dithio ammonium formiate, and its reaction formula is as follows:
⑵ add acetonitrile in reaction vessel, then stirring reaction 1~2h rises to reacting liquid temperature 85~90 ℃, stirs insulation backflow 0.5~1h, obtains 2-sulfydryl-5-methyl isophthalic acid, 3,4-thiadiazoles ammonium salt aqueous solution, and its reaction formula is as follows:
⑶ when treat below the greenhouse cooling to 40 ℃ of the reaction vessel among the step ⑵, drip hcl acidifying and obtain 2-methyl-5-sulfydryl-1,3,4-thiadiazoles suspension liquid, filtration washing obtain the oyster white crystal powder and are 2-sulfydryl-5-methyl isophthalic acid, 3,4-thiadiazoles crude product, purified drying obtains white crystalline powder 2-sulfydryl-5-methyl isophthalic acid, 3 again, the 4-thiadiazoles, its reaction formula is as follows:
At above-mentioned a kind of 2-sulfydryl-5-methyl isophthalic acid, among the preparation method of 3,4-thiadiazoles, in step ⑴, the mass ratio of described ammoniacal liquor and hydrazine hydrate is 2~2.4:1.
At above-mentioned a kind of 2-sulfydryl-5-methyl isophthalic acid, among the preparation method of 3,4-thiadiazoles, in step ⑵, the mass ratio of described acetonitrile and hydrazine hydrate is 1.9~2.2:1.
At above-mentioned a kind of 2-sulfydryl-5-methyl isophthalic acid, among the preparation method of 3,4-thiadiazoles, in step ⑶, described concentration of hydrochloric acid is 35%~38%.
The present invention and existing 2-sulfydryl-5-methyl isophthalic acid, the preparation method of 3,4-thiadiazoles compares, and has following characteristics:
1, raw materials used relative minimizing, processing step are simplified, and one step of building-up process goes down, and has not only shortened the production cycle, has reduced raw materials cost, have also improved product yield and quality product is true.
2, in building-up process, without organic solvents such as methanol/ethanol, reaction is become with the reaction of water as solvent.In the water solvent reaction with organic solvent in the reacting phase ratio, at water as under the solvent condition, operation is simple, do not need again with separated from solvent out, save energy, the loss that has prevented simultaneously intermediate product is run off, and has improved product yield, has prevented the generation of waste and the advantage of poisonous and hazardous material environmental pollution.
Embodiment
Below by embodiment the present invention is made further and to specify, but the present invention is not limited only to these embodiment.
Embodiment 1:
Put into successively 50 grams, 100% hydrazine hydrate in 500 milliliters of building-up reactions bottles, 120 restrain 20% ammoniacal liquor, stir temperature is dropped to below 5 ℃ under the frozen water cooling.Begin to drip dithiocarbonic anhydride 90 grams, finish to continue again to remain on below 5 ℃ and stirred 1 hour.Obtain the aqueous solution of diazanyl dithio ammonium formiate.
Solution obtained above is changed over to 1000 milliliters reaction flask, add 100 gram acetonitriles, naturally stir half hour, be warming up to again 85~90 ℃ of insulations 1 hour.Then solution is cooled to below 40 ℃, drips 30% hydrochloric acid in 30 ℃ to 35 ℃ scopes, transfer pH to 4 to 4.5, stir half an hour, suction filtration is washed 3 times, obtains the wet product 130g of thiadiazoles.
The wet product that obtain with ammonia solvent, decolouring, insulation, filtration, acidifying, suction filtration, dry to get thiadiazoles elaboration 79g.Through HPLC liquid phase analysis, product content 99.8%.
Embodiment 2:
Put into successively 50 grams, 100% hydrazine hydrate in 500 milliliters of building-up reactions bottles, 120 restrain 20% ammoniacal liquor, stir temperature is dropped to below 5 ℃ under the frozen water cooling.Begin to drip dithiocarbonic anhydride 80 grams, finish to continue again to remain on below 5 ℃ and stirred 1 hour.Obtain the aqueous solution of diazanyl dithio ammonium formiate.
Solution obtained above is changed over to 1000 milliliters reaction flask, add 100 gram acetonitriles, naturally stir half hour, be warming up to again 85~90 ℃ of insulations 1 hour.Then solution is cooled to below 40 ℃, drips 35% hydrochloric acid in 30 ℃ to 35 ℃ scopes, transfer pH to 4 to 4.5, stir half an hour, suction filtration is washed 3 times, obtains the wet product 142g of thiadiazoles.
The wet product that obtain with ammonia solvent, decolouring, insulation, filtration, acidifying, suction filtration, dry to get thiadiazoles elaboration 85g.Through HPLC liquid phase analysis, product content 99.9%.
Embodiment 3:
Put into successively 50 grams, 100% hydrazine hydrate in 500 milliliters of building-up reactions bottles, 120 restrain 20% ammoniacal liquor, stir temperature is dropped to below 5 ℃ under the frozen water cooling.Begin to drip dithiocarbonic anhydride 80 grams, finish to continue again to remain on below 5 ℃ and stirred 1 hour.Obtain the aqueous solution of diazanyl dithio ammonium formiate.
Solution obtained above is changed over to 1000 milliliters reaction flask, add 105 gram acetonitriles, naturally stir half hour, be warming up to again 85~90 ℃ of insulations 1 hour.Then solution is cooled to below 40 ℃, drips 35% hydrochloric acid in 30 ℃ to 35 ℃ scopes, transfer pH to 4 to 4.5, stir half an hour, suction filtration is washed 3 times, obtains the wet product 135g of thiadiazoles.
The wet product that obtain with ammonia solvent, decolouring, insulation, filtration, acidifying, suction filtration, dry to get thiadiazoles elaboration 82g.Through HPLC liquid phase analysis, product content 99.9%.