تفاعل #2188

معادلة التفاعل

(±)-ethyl 4-[5-[2-[1-(4-chlorobenzoyl)propyl]-2,3-dihydro-3-oxo-4H-1,2,4-triazol-4-yl]-2-pyridinyl]-1-piperazinecarboxylate

→

(±)-2-[1-(4-chlorobenzoyl)propyl]-2,4-dihydro-4-[6-(1-piperazinyl)-3-pyridinyl]-3H-1,2,4-triazol-3-one monohydrochloride

المردود 39.4%

المذيبات

hydrobromic acid

water

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةrefluxed overnight
2. 2
   أخرىThe solvent was evaporated
3. 3
   workup.DISSOLUTIONthe residue was dissolved in CH2Cl2
4. 4
   استخلاصextracted with CH2 Cl2
5. 5
   غسيلThe organic layer was washed with water
6. 6
   أخرىdried
7. 7
   ترشيحfiltered
8. 8
   أخرىevaporated
9. 9
   أخرىA sample (3.5 g) of the residue (total 18 g) was purified by column chromatography over silica gel (eluent: CH2Cl2 /(CH3OH/NH3) 99/1)
10. 10
    أخرىThe pure fractions were collected
11. 11
    أخرىevaporated
12. 12
    workup.DISSOLUTIONThe residue was dissolved in 2-propanol
13. 13
    أخرىcrystallized into the hydrochloric acid salt (1:1) in 2-propanol
14. 14
    ترشيحThe precipitate was filtered off
15. 15
    غسيلwashed with 2-propanol
16. 16
    أخرىdried at 150° C
17. 17
    workup.DISSOLUTIONThe product was dissolved in 2-propanol
18. 18
    workup.ADDITIONPyridine was added dropwise until all the product
19. 19
    workup.DISSOLUTIONwas dissolved
20. 20
    أخرىsubsequently crystallized
21. 21
    ترشيحThe precipitate was filtered off
22. 22
    أخرىdried

الإجراء التجريبي

A mixture of (±)-ethyl 4-[5-[2-[1-(4-chlorobenzoyl)propyl]-2,3-dihydro-3-oxo-4H-1,2,4-triazol-4-yl]-2-pyridinyl]-1-piperazinecarboxylate (24 g) in hydrobromic acid, 48% solution in water (250 ml) was stirred and refluxed overnight. The solvent was evaporated and the residue was dissolved in CH2Cl2, neutralized with NH4OH/H2O and extracted with CH2 Cl2. The organic layer was washed with water, dried, filtered and evaporated. A sample (3.5 g) of the residue (total 18 g) was purified by column chromatography over silica gel (eluent: CH2Cl2 /(CH3OH/NH3) 99/1). The pure fractions were collected and evaporated. The residue was dissolved in 2-propanol and crystallized into the hydrochloric acid salt (1:1) in 2-propanol. The precipitate was filtered off, washed with 2-propanol and dried at 150° C. The product was dissolved in 2-propanol. Pyridine was added dropwise until all the product was dissolved and subsequently crystallized. The precipitate was filtered off and dried, yielding 1.7 g (±)-2-[1-(4-chlorobenzoyl)propyl]-2,4-dihydro-4-[6-(1-piperazinyl)-3-pyridinyl]-3H-1,2,4-triazol-3-one monohydrochloride (39.4%); mp. 209.8° C. (interm. 1).

المصدر