Reaktion #1375806

Reaktionsgleichung

intermediate 1-b

1,1-dimethylethyl [(4-chlorophenyl)(1 -methyl-1H-benzotriazol-6-yl)-methylene]hydrazine carboxylate

hydrochloric acid

water

→

(±)-6-[(4-chlorophenyl)hydrazinomethyl]-1-methyl-1H-benzotriazole monohydrochloride

Lösungsmittel

tetrahydrofuran

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe whole was heated
2. 2
   Temperaturto reflux
3. 3
   Temperaturrefluxed for 1.5 hours
4. 4
   TemperaturThe mixture was cooled to room temperature
5. 5
   workup.STIRRINGAfter stirring for 1 hour
6. 6
   Filtrationthe reaction mixture was filtered
7. 7
   workup.ADDITIONThe filtrate was mixed with 75 ml of methylbenzene
8. 8
   SonstigeThe layers were separated
9. 9
   ExtraktionThe product was extracted with dichloromethane
10. 10
    Sonstigethe extract was dried
11. 11
    Filtrationfiltered
12. 12
    Sonstigeevaporated
13. 13
    workup.ADDITIONby adding 3ml of a mixture of hydrochloric acid in 2-propanol (4.8N)
14. 14
    workup.STIRRINGAfter stirring for 2 hours the product
15. 15
    Filtrationwas filtered off
16. 16
    Waschenwashed with 2-propanol
17. 17
    Sonstigedried in vacuo at 50° C.

Vorschrift

To a suspension of 10 g of intermediate 1-b in 60 ml of tetrahydrofuran under a nitrogen atmosphere were added dropwise over 15 minutes 26 ml of a borane tetrahydrofuran complex in tetrahydrofuran (1M). After stirring for 15 minutes at ±22° C. there were added 13 ml of hydrochloric acid (6N). The whole was heated to reflux and refluxed for 1.5 hours. The mixture was cooled to room temperature and 50 ml of water were added. After stirring for 1 hour, the reaction mixture was filtered. The filtrate was mixed with 75 ml of methylbenzene. The layers were separated and the aqueous layer was basified (pH 7.5-8) with NH4OH. The product was extracted with dichloromethane and the extract was dried, filtered and evaporated. The residue was converted into the hydrochloride salt in 2-propanol by adding 3ml of a mixture of hydrochloric acid in 2-propanol (4.8N). After stirring for 2 hours the product was filtered off, washed with 2-propanol and dried in vacuo at 50° C., yielding 2.1 g of (±)-6-[(4-chlorophenyl)hydrazinomethyl]-1-methyl-1H-benzotriazole monohydrochloride (interm. 2-e).

Quelle