Ethanol → Ethyl 2'-amino-4'-methyl-4,5'-bi-1,3-thiazole-2-carboxylate

HRID 1715274Notes

Reaction equation

HRID 1715274 reaction equation
C([NH:4][C:5]1[S:6][C:7]([C:11]2[N:12]=[C:13]([C:16](NCC=C)=[O:17])[S:14][CH:15]=2)=[C:8]([CH3:10])[N:9]=1)(=O)C.[C:22](OCC)(=S)[C:23](N)=O.CC[OH:32]>>[NH2:4][C:5]1[S:6][C:7]([C:11]2[N:12]=[C:13]([C:16]([O:17][CH2:22][CH3:23])=[O:32])[S:14][CH:15]=2)=[C:8]([CH3:10])[N:9]=1

Participants

4

Reactant 3

HCID 702EthanolHCID 119612582'-(Acetylamino)-N-allyl-4'-methyl-4,5'-bi-1,3-thiazole-2-carboxamide2×HCID 216137632-ethoxy-2-thioxoAcetamide

Product 1

HCID 87443161Ethyl 2'-amino-4'-methyl-4,5'-bi-1,3-thiazole-2-carboxylate

Conditions

Temperature
120 °C

Procedure

In a microwave tube, 1-(2-amino-4-methyl-1,3-thiazol-5-yl)-2-bromo ethanone, hydrobromide salt (Intermediate 2)(400 mg; 1.27 mmol; 1 eq.) is suspended in EtOH (7 ml). Ethyl thiooxamate (168.6 mg; 1.27 mmol; 1 eq.) is added and the mixture is heated at 120° C. for 15 min under microwave irradiation. The reaction is complete and a precipitate is formed. It is filtered and washed with EtOH, affording ethyl 2′-amino-4′-methyl-4,5′-bi-1,3-thiazole-2-carboxylate as its hydrobromide salt (201 mg; 45.3%). It is suspended in DCM/EtOH 2:1 mixture (9 ml) and Amberlyst A-21 (200 mg; 4.54 mmol; 3.58 eq.) is added. The mixture is shaken for 2 h30, filtrated and the solvents are evaporated, affording ethyl 2′-amino-4′-methyl-4,5′-bi-1,3-thiazole-2-carboxylate as yellow powder (146.2 mg; 43%). 1H NMR (DMSO-d6, 300 MHz) δ 1.33 (t, J=6 Hz, 3H), 2.32 (s, 3H), 4.38 (q, J=6 Hz, 2H), 7.17 (br s, 2H), 7.82 (s, 1H). M− (ESI): 268.17; M+ (ESI): 270.16. HPLC (method A), Rt: 1.54 min (purity: 99.6%).

Workup

  1. customa precipitate is formed
  2. filtrationIt is filtered
  3. washwashed with EtOH

Sources & evidence

ORD record
ord-a52c6dc7011445d0aadb9ed282933e26
Source dataset
uspto-grants-2010_09
Patent number
US07799814B2

Reaction notes

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