Ethyl orthoformate → ethyl 4-methyl-2-(5-oxo-1H-1,2,4-triazol-4(5H)-yl)thiazole-5-carboxylate

HRID 554921Notes

Reaction equation

HRID 554921 reaction equation
[NH:1]([C:3]([NH:5][C:6]1[S:7][C:8]([C:12]([O:14][CH2:15][CH3:16])=[O:13])=[C:9]([CH3:11])[N:10]=1)=[O:4])[NH2:2].[CH:17](OCC)(OCC)OCC>>[CH3:11][C:9]1[N:10]=[C:6]([N:5]2[C:3](=[O:4])[NH:1][N:2]=[CH:17]2)[S:7][C:8]=1[C:12]([O:14][CH2:15][CH3:16])=[O:13]

Participants

3

Reactant 2

HCID 31214Ethyl orthoformateHCID 86635202Ethyl 2-(hydrazinecarboxamido)-4-methylthiazole-5-carboxylate

Product 1

HCID 57920013ethyl 4-methyl-2-(5-oxo-1H-1,2,4-triazol-4(5H)-yl)thiazole-5-carboxylateYield 80%

Conditions

Temperature
95 °C

Procedure

To a 2-neck round bottom flask (1 L) equipped with a mechanical stirrer was added ethyl 2-(hydrazinecarboxamido)-4-methylthiazole-5-carboxylate (42.00 g, 172.00 mmol) in anhydrous triethyl orthoformate (393 mL). The yellow reaction mixture was heated at 95° C. for 2 h, and then cooled to ambient temperature. The precipitate was filtered and washed with cold methanol (100 mL) to afford the title compound as a colourless solid (34.9 g, 80%): mp 165-167° C.; 1H NMR (300 MHz, DMSO-d6) δ 12.94 (br, 1H), 9.09 (s, 1H), 4.64 (t, J=7.1 Hz, 2H), 2.98 (s, 3H), 1.67 (t, J=7.1 Hz, 3H); 13C NMR (75 MHz, DMSO-d6) δ 162.3, 157.1, 154.5, 152.3, 133.6, 118.4, 61.9, 17.7, 14.9; MS (ES+) m/z 255.0 (M+1).

Workup

  1. customTo a 2-neck round bottom flask (1 L) equipped with a mechanical stirrer
  2. temperaturecooled to ambient temperature
  3. filtrationThe precipitate was filtered
  4. washwashed with cold methanol (100 mL)

Sources & evidence

ORD record
ord-651ef82fa76e4d36ae53594ed30f496b
Source dataset
uspto-grants-2011_11
Patent number
US08049016B2

Reaction notes

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