Reaktion #10807

Reaktionsgleichung

Sodium azide

HCl

isopropanol

isopropanol

(2-Acetyl-5-methoxy-4-thiophen-2-yl-phenoxy)-acetonitrile

→

4-methoxy-2-(1H-tetrazol-5-ylmethoxy)-5-thiophen-2-yl-benzaldehyde

Ausbeute 65.0%

Lösungsmittel

ethyl acetate

tetrahydrofuran

water

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwere added
2. 2
   Temperaturthe reaction was heated
3. 3
   Temperaturto reflux
4. 4
   Temperaturat reflux due to evaporation
5. 5
   Sonstigewas obtained (1 h)
6. 6
   SonstigeThe layers were separated
7. 7
   Extraktionthe aqueous was extracted with ethyl acetate (3×50 mL)
8. 8
   TrocknenThe combined organic extracts were dried over sodium sulfate
9. 9
   Einengenconcentrated to a dark green solid

Vorschrift

Ex-89B: (2-Acetyl-5-methoxy-4-thiophen-2-yl-phenoxy)-acetonitrile (Ex-89A, 0.30 g, 1.1 mmol) was slurried in a mixture of water:isopropanol (3 mL, 2:1) to obtain a well-dispersed solution. Sodium azide (0.079 g, 1.2 mmol) followed by zinc bromide (0.25 g, 1.1 mmol) were added and the reaction was heated to reflux and vigorously stirred for 24 h. Additional solvent (1 mL, 1:1 water:isopropanol) was added after 10 h at reflux due to evaporation. The reaction was diluted with an ethyl acetate:tetrahydrofuran mixture (25 mL, 2:1) and a 3 N HCl solution (10 mL) and vigorously stirred until a homogenous solution was obtained (1 h). The layers were separated and the aqueous was extracted with ethyl acetate (3×50 mL). The combined organic extracts were dried over sodium sulfate and concentrated to a dark green solid. Silica gel chromatography (15% methanol/methylene chloride containing 1% acetic acid) gave 0.22 g (65%) of 4-methoxy-2-(1H-tetrazol-5-ylmethoxy)-5-thiophen-2-yl-benzaldehyde as a pale green solid. 1H-NMR (300 MHz, DMSO-d6) δ 10.33 (s, 1H), 7.97 (s, 1H), 7.52–7.56 (m, 2H), 7.10–7.12 (m, 2H), 5.81 (s, 2H), 4.05 (s, 3H). MS (ESI) m/z=317 ([M+H]+, 100%), HRMS (ESI) Calcd. for C27H25NO7S: 317.0708. Found: 317.0712.

Quelle