Hydrazinecarboxylic acid, ethyl ester → 1,8-Dimethyl-6-propylimidazo[1,5-d][1,2,4]triazin-4(3H)-one

HRID 543876Notes

Reaction equation

HRID 543876 reaction equation
[CH2:1]([C:4]1[NH:5][C:6]([CH3:12])=[C:7]([C:9]([CH3:11])=O)[N:8]=1)[CH2:2][CH3:3].[C:13](OCC)(=[O:16])[NH:14][NH2:15]>C(O)(=O)C.C(O)CCC>[CH3:11][C:9]1[C:7]2[N:8]([C:4]([CH2:1][CH2:2][CH3:3])=[N:5][C:6]=2[CH3:12])[C:13](=[O:16])[NH:14][N:15]=1

Participants

5

Reactant 2

HCID 20064Hydrazinecarboxylic acid, ethyl esterHCID 131770121-(5-Methyl-2-propyl-1H-imidazol-4-yl)ethan-1-one

Product 1

HCID 131770131,8-Dimethyl-6-propylimidazo[1,5-d][1,2,4]triazin-4(3H)-one

Reagents, catalysts & solvents 2

HCID 176Acetic AcidCatalystHCID 2631-ButanolSolvent

Conditions

Temperature
50 °C

Procedure

A mixture of 59.7 g. of methyl 2-n-propyl-5-methyl-4-imidazolyl ketone, 41.14 g. of ethyl carbazate, 200 ml. of n-butanol and 4 drops of glacial acetic acid is warmed until solution is complete and then heated under reflux for 5 hours. The solution is concentrated in vacuo to an oily residue, 250 ml. of diphenyl ether are added and the resulting solution is heated with stirring in an oil bath for 30 minutes after the start of gas evolution. The temperature is maintained as closely as possible to the point at which gas evolution starts (150°-250°C.). The reaction is removed from the oil bath, cooled to 50° C. and diluted with 1-2 volumes hexane. The product is collected, washed with petroleum ether and then dissolved in 200 ml. of chloroform. This solution is filtered through 250 ml. of Magnesol® followed by an 800 ml. chloroform wash. The filtrate is concentrated in vacuo and the residue is recrystallized from 250 ml. of ethyl acetate, giving 48.2 g. of the desired product as off-white crystals, m.p. 154°-155° C.

Workup

  1. additionA mixture of 59.7 g
  2. temperatureheated
  3. temperatureunder reflux for 5 hours
  4. concentrationThe solution is concentrated in vacuo to an oily residue, 250 ml
  5. additionof diphenyl ether are added
  6. temperaturethe resulting solution is heated
  7. temperatureThe temperature is maintained as closely as possible to the point at which gas evolution
  8. custom(150°-250°C.)
  9. customThe reaction is removed from the oil bath
  10. additiondiluted with 1-2 volumes hexane
  11. customThe product is collected
  12. washwashed with petroleum ether
  13. dissolutiondissolved in 200 ml
  14. filtrationThis solution is filtered through 250 ml
  15. washchloroform wash
  16. concentrationThe filtrate is concentrated in vacuo
  17. customthe residue is recrystallized from 250 ml
  18. customof ethyl acetate, giving 48.2 g

Sources & evidence

ORD record
ord-f73e6f2936804319b77df2ea74a6b7e6
Source dataset
uspto-grants-1984_05
Patent number
US04447603

Reaction notes

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