Reacción #2139930

Ecuación de reacción

N,N-diphenylhydrazine hydrochloride

4-diethylamino-2-hydroxybenzaldehyde

sodium carbonate

→

4-Diethylamino-2-hydroxybenzaldehyde N,N-diphenylhydrazone

Disolventes

ethanol

ethanol

Condiciones de reacción

Tratamiento posterior

1. 1
   Otroreacted in about ½ hour
2. 2
   OtroThe residue obtained
3. 3
   Otroafter evaporation of the solvent (800 ml)
4. 4
   workup.ADDITIONwas treated with ether
5. 5
   Extracciónthe ether extract
6. 6
   Lavadowas washed with water until the pH of the water
7. 7
   SecadoThe organic layer was dried over anhydrous magnesium sulphate
8. 8
   workup.ADDITIONtreated with activated charcoal
9. 9
   Filtraciónfiltered
10. 10
    OtroThe ether solvent was evaporated
11. 11
    Otrothe residue was recrystallized from ethanol
12. 12
    FiltraciónCrystalline 4-diethylamino-2-hydroxybenzaldehyde N,N-diphenylhydrazone was filtered off
13. 13
    Lavadowashed with cold ethanol
14. 14
    Otroto be 95.5-96.5° C.
15. 15
    Otrorecrystallized from a mixture of 2-propanol and ether in a 10:1 ratio by volume)
16. 16
    OtroAn elemental analysis yielded the
17. 17
    Otrofollowing results in weight percent

Procedimiento

A solution of N,N-diphenylhydrazine hydrochloride (79.5 g, 0.36 mol, from Aldrich, Milwaukee, Wis.) in ethanol (500 ml) was slowly added to a solution of 4-diethylamino-2-hydroxybenzaldehyde (58.0 g, 0.3 mol, from Aldrich, Milwaukee, Wis.) in ethanol (500 ml) in the presence of excess sodium carbonate. The reaction mixture was refluxed until all of the aldehyde reacted in about ½ hour. The residue obtained after evaporation of the solvent (800 ml) was treated with ether and the ether extract was washed with water until the pH of the water reached 7. The organic layer was dried over anhydrous magnesium sulphate, treated with activated charcoal, and filtered. The ether solvent was evaporated and the residue was recrystallized from ethanol. Crystalline 4-diethylamino-2-hydroxybenzaldehyde N,N-diphenylhydrazone was filtered off and washed with cold ethanol. The yield of the product was 85 g (78.8%). The melting point was found to be 95.5-96.5° C. (recrystallized from a mixture of 2-propanol and ether in a 10:1 ratio by volume). The 1H-NMR spectrum (100 MHz) of the product in CDCl3 was characterized by the following chemical shifts (δ, ppm): 11.55 (s, 1H, OH); 7.55-6.95 (m, 11H, CH═N, Ph); 6.7 (d, J=8.6 Hz; 1H, 6-H of 1,2,4-subst. Ph); 6.23 (s, 1H, 3-H of 1,2,4-subst. Ph); 6.1 (d, J=8.6 Hz, 1H, 5-H of 1,2,4-subst. Ph); 3.3 (q, J=8.0 Hz, 4H, CH2); 1.1 (t, J=8.0 Hz, 6H, CH3). An elemental analysis yielded the following results in weight percent: C, 76.68; H, 7.75; N, 11.45, which compared with calculated values for C23H25N3O in weight percent of: C, 76.85; H, 7.01; N, 11.69.

Fuente