girard’s reagent t girard’s reagent t

structural formula

• numbering system
• physical property data
• toxicological data
• ecological data
• molecular structure data
• computing chemical data
• more
  • properties and stability
  • storage method
  • synthesis method
  • purpose

numbering system

cas number:123-46-6

mdl number:mfcd00012009

einecs number:204-629-3

rtecs number:cp3150000

brn number:3727163

pubchem number:24895356

physical property data

1. properties: white needle-like crystals. strong hygroscopicity

2. melting point: 188-192℃ (decomposition)

3. solubility: easily soluble in water, soluble in 150 parts of absolute ethanol, soluble in ice acetic acid, glycerin and ethylene glycol

toxicological data

1. acute toxicity: rat oral ld: >500mg/kg

ecological data

none yet

molecular structure data

none yet

compute chemical data

1. reference value for hydrophobic parameter calculation (xlogp): none

2. number of hydrogen bond donors: 2

3. number of hydrogen bond acceptors: 3

4. number of rotatable chemical bonds: 2

5. number of tautomers: 2

6. topological molecule polar surface area 55.1

7. number of heavy atoms: 10

8. surface charge: 0

9. complexity: 105

10. number of isotope atoms: 0

11. determine the number of atomic stereocenters: 0

12. uncertain number of atomic stereocenters: 0

13. determine the number of chemical bond stereocenters: 0

14. number of uncertain chemical bond stereocenters: 0

15. number of covalent bond units: 2

properties and stability

1. properties: white needle-like crystals. highly hygroscopic.

storage method

none yet

synthesis method

1. preparation method: mix ethyl chloroacetate and absolute ethanol, cool to 0°c, add trimethylamine pre-cooled to -5°c, control the exothermic reaction, and raise the reaction temperature to 60°c, after stopping the heat generation, place it at room temperature for 24 hours, add dropwise 100% hydrazine hydrate, stir for 45 minutes, cool, filter out the crystals, and dry to obtain giralde’s reagent t, with a yield of 83.5%-89.5%.

2. add 98.5 grams (84.5 liters, 0.8 mol) ethyl chloroacetate and 200 ml of absolute ethanol. cool to 0°c, stop stirring, add 49 grams (74 ml, 0.83 mol) of trimethylamine pre-cooled to -5°c at one time, and use cooling to fully control the release.carry out the reaction so that the temperature of the reactants rises to 60°c within about 10 working hours. after no longer exothermic, let the reactants stand at room temperature for 20 to 24 hours. remove the condenser, replace the thermometer with a dropping funnel, add 40 grams (0.8 mol) of 100% hydrazine hydrate dropwise within 10-15 minutes under stirring, and continue stirring for 45 minutes. after the solution is slightly cooled, if the product does not crystallize automatically, rub the bottle wall with a glass rod to stimulate crystallization. the product will appear as fine colorless needle-shaped crystals. cool in an ice bath, quickly filter out the easily deliquescent salt, wash with 1}} liters of absolute ethanol, press dry, and dry in a vacuum dryer filled with concentrated sulfuric acid. the product weighs 100 to 108 grams. after evaporating 200-300 ml of solvent from the mother liquor, a second batch of products was obtained, with a total weight of 112-120 grams (83.5-89.5%). the product should be stored in a dry, airtight container. after the product has been placed for a period of time,
it is best to recrystallize it with absolute ethanol before use.

purpose

1. used to separate estrone and 17-steroid compounds.

2.separate ketones from mixtures containing non-ketone substances. also used in some dehydration reactions.