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

HRID 2067513Notes

Reaction equation

HRID 2067513 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](OC)(OC)OC.O.C1(C)C=CC(S(O)(=O)=O)=CC=1>CO>[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

5

Reactant 3

HCID 9005Trimethyl orthoformateHCID 521998p-Toluenesulfonic acid monohydrateHCID 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 73%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A solution of ethyl 2-(hydrazinecarboxamido)-4-methylthiazole-5-carboxylate (0.50 g, 2.05 mmol), trimethyl orthoformate (0.25 mL, 2.28 mmol) and p-toluenesulfonic acid monohydrate (10 mg) in methanol (10 mL) was subjected to microwave irradiation for 10 minutes at 90° C. (30 psi). The solvent was removed in vacuo and the residue was suspended in dichloromethane. The solid was collected by filtration, washed with saturated sodium bicarbonate and water, and dried to afford the title compound in 73% yield (0.38 g): 1H NMR (300 MHz, DMSO-d6) δ 8.33 (s, 1H), 4.32 (q, J=6.9 Hz, 2H), 2.68 (s, 3H), 1.35 (t, J=6.9 Hz, 3H); MS (ES+) m/z 255.2 (M+1).

Workup

  1. customirradiation for 10 minutes at 90° C. (30 psi)
  2. customThe solvent was removed in vacuo
  3. filtrationThe solid was collected by filtration
  4. washwashed with saturated sodium bicarbonate and water
  5. customdried

Sources & evidence

ORD record
ord-7e65a3576a26437ab12a777701b6e2ee
Source dataset
uspto-grants-2012_10
Patent number
US08293768B2

Reaction notes

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