Reaktion #955935

Reaktionsgleichung

thiosemicarbazide

4-ethyl-2-methoxybenzoic acid

EDCI

→

5-(4-ethyl-2-methoxyphenyl)-2H-1,2,4-triazole-3(4H)-thione

Ausbeute 55.0%

Lösungsmittel

pyridine

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGthe reaction was stirred at r.t. for 24 h
2. 2
   SonstigeThe mixture was evaporated to dryness
3. 3
   workup.ADDITIONdiluted with water
4. 4
   SonstigeA white solid was collected
5. 5
   Waschenwashed with water
6. 6
   Temperaturheated
7. 7
   Temperaturat reflux for 2 days
8. 8
   FiltrationThe suspension was filtered hot
9. 9
   Temperaturthe aqueous solution was cooled in ice
10. 10
    SonstigeThe solid was collected
11. 11
    Waschenwashed with water
12. 12
    Sonstigedried

Vorschrift

To a solution of 4-ethyl-2-methoxybenzoic acid (example 18b) (1 g, 6.1 mmol) in pyridine (6 mL) was added EDCI (1.2 g, 6.3 mmol) and the suspension was stirred at r.t. for 2 h. Then thiosemicarbazide (547 mg, 6 mmol) was added and the reaction was stirred at r.t. for 24 h. The mixture was evaporated to dryness and then diluted with water. A white solid was collected and washed with water. The solid was suspended in aq. NaHCO3 (1M, 20 mL) and heated at reflux for 2 days. The suspension was filtered hot and the aqueous solution was cooled in ice and acidified to pH 3 with conc. HCl. The solid was collected washed with water and dried to give 5-(4-ethyl-2-methoxyphenyl)-2H-1,2,4-triazole-3(4H)-thione as a white powder (55%). MS (M+H, 236).

Quelle