ChemicalBook CAS DataBase List Ethyl2,5-dihydro-5-oxo-1-phenyl-1H-1,2,4-triazole-3-carboxylate

Ethyl2,5-dihydro-5-oxo-1-phenyl-1H-1,2,4-triazole-3-carboxylate synthesis

6synthesis methods

Product Name:Ethyl2,5-dihydro-5-oxo-1-phenyl-1H-1,2,4-triazole-3-carboxylate
CAS Number:67267-08-7
Molecular formula:C11H11N3O3
Molecular Weight:233.22

32315-10-9 Synthesis

32315-10-9
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36999-43-6 Synthesis

Ethyl2-amino-2-(2-phenylhydrazono)acetate

36999-43-6
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$395.00/1g

Ethyl2,5-dihydro-5-oxo-1-phenyl-1H-1,2,4-triazole-3-carboxylate

67267-08-7
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Yield:67267-08-7 295 mg

Reaction Conditions:

in tetrahydrofuran at 0 - 18; for 20 h;Inert atmosphere;

Steps:

B Step B:
Ethyl 5-oxo-1-phenyl-4H-1,2,4-triazole-3-carboxylate

To a solution of ethyl (2Z)-2-amino-2-(phenylhydrazono)acetate (600 mg, crude) in distilled tetrahydrofuran (20 mL) was added triphosgene (860 mg, 2.90 mmol) at 0° C.
The reaction mixture was stirred at 0° C. for 2 h, then at room temperature for 18 h.
The reaction mixture was diluted with water (20 mL) and extracted with ethyl acetate (2*20 mL).
The combined organic layers were washed with brine (2*10 mL), dried over sodium sulfate, filtered and evaporated.
Purification (FCC, SiO₂, n-heptane:ethyl acetate (100:0→50:50) afforded the title compound (295 mg, 43% yield) as a white powder. MS (ESI): mass calcd. for C₁₁H₁₁N₃O₃, 233.1; m/z found, 234.1 [M+H]⁺.

References:

US2020/102311,2020,A1 Location in patent:Paragraph 0410; 0577

2295-31-0 Synthesis