Reaktion #795015

Reaktionsgleichung

diisopropylethylamine

isopropylhydrazine hydrochloride

NaOH

sodium bicarbonate

NaOCl

8-bromo-4,5-dihydro-6-oxa-3-thia-1-aza-benzo[e]azulene-2-carboxylic acid

diisopropylethylamine

HATU

1-benzyloxycarbonyl-2-methyl-isothiourea

→

[5-(8-Bromo-4,5-dihydro-6-oxa-3-thia-1-aza-benzo[e]azulen-2-yl)-1-isopropyl-1H-[1,2,4]triazol-3-yl]-carbamic acid benzyl ester

Ausbeute 57.0%

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas added
2. 2
   Extraktionthe mixture extracted with 1:1 EtOAc/THF solution (×2)
3. 3
   Waschenwashed with brine
4. 4
   Trocknendried (Na2SO4)
5. 5
   Einengenconcentrated in vacuo
6. 6
   workup.ADDITIONThe resulting solid was added to DMF (50 mL)
7. 7
   Temperaturto cool to RT
8. 8
   Extraktionextracted with EtOAc
9. 9
   Waschenwashed with water
10. 10
    TrocknenThe organic layer was dried (Na2SO4)
11. 11
    Einengenconcentrated in vacuo
12. 12
    SonstigeThe resultant residue was purified by flash chromatography (SiO2, gradient 0-50% EtOAc in cyclohexane)

Vorschrift

To a suspension of 8-bromo-4,5-dihydro-6-oxa-3-thia-1-aza-benzo[e]azulene-2-carboxylic acid (1.86 g, 5.70 mmol) in anhydrous THF (75 mL) was added diisopropylethylamine (2 mL, 11.4 mmol), HATU (2.39 g, 6.27 mmol) and 1-benzyloxycarbonyl-2-methyl-isothiourea (1.47 g, 6.56 mmol) at RT. After stirring for 24 hours an aqueous saturated sodium bicarbonate solution was added and the mixture extracted with 1:1 EtOAc/THF solution (×2). The organic layers were combined, washed with brine, dried (Na2SO4) and concentrated in vacuo. The resulting solid was added to DMF (50 mL) and treated with diisopropylethylamine (4 mL, 22.8 mmol) and isopropylhydrazine hydrochloride (941 mg, 8.55 mmol). The mixture was heated to 95° C. and scrubbed with 1N NaOH solution and NaOCl solution. After 2 hours the mixture was allowed to cool to RT, extracted with EtOAc and washed with water. The organic layer was dried (Na2SO4) and concentrated in vacuo. The resultant residue was purified by flash chromatography (SiO2, gradient 0-50% EtOAc in cyclohexane) to afford [5-(8-Bromo-4,5-dihydro-6-oxa-3-thia-1-aza-benzo[e]azulen-2-yl)-1-isopropyl-1H-[1,2,4]triazol-3-yl]-carbamic acid benzyl ester (1.75 g, 57%). LCMS: RT=5.11 min, [M+H]+=540/542

Quelle