N-bromobutanimide → Ethyl 5-bromo-2-(pyridin-3-yl)thiazole-4-carboxylate

HRID 533323ノート

反応式

HRID 533323 の反応式
[N:1]1[CH:6]=[CH:5][CH:4]=[C:3]([C:7]2[S:8][CH:9]=[C:10]([C:12]([O:14][CH2:15][CH3:16])=[O:13])[N:11]=2)[CH:2]=1.C[Si]([N-][Si](C)(C)C)(C)C.[K+].[Br:27]N1C(=O)CCC1=O>O1CCCC1>[Br:27][C:9]1[S:8][C:7]([C:3]2[CH:2]=[N:1][CH:6]=[CH:5][CH:4]=2)=[N:11][C:10]=1[C:12]([O:14][CH2:15][CH3:16])=[O:13]

参加物

5

反応物 3

HCID 67184N-bromobutanimideHCID 2824169Ethyl 2-(pyridin-3-YL)thiazole-4-carboxylateHCID 3251421Potassium bis(trimethylsilyl)amide

生成物 1

HCID 59580826Ethyl 5-bromo-2-(pyridin-3-yl)thiazole-4-carboxylate収率 52.6%

試薬・触媒・溶媒 1

HCID 8028Tetrahydrofuran溶媒2 回

実験手順

A tetrahydrofuran (15 mL) solution of ethyl 2-(pyridin-3-yl)thiazole-4-carboxylate (1.17 g, 5.0 mmol) was added to −78° C. solution of potassium bis(trimethylsilyl)amide (12 mL, 6 mmol, 0.5 M in toluene) over 2 min. This reaction mixture was allowed to stir for 1.5 h and then was transferred via canula into a −78° C. solution of N-bromosuccinimide (1.35 g, 7.5 mmol) in tetrahydrofuran (5 mL). This mixture was stirred for 5 min and then the reaction vessel was removed from the cooling bath and allowed to warm to room temperature over 3 h. The reaction was quenched by pouring into a mixture of ether and water. The layers were separated and the aqueous layer was extracted twice with ethyl acetate. The combined organics were dried over MgSO4, filtered, and the solvent was removed in vacuo. The residue was subjected to silica gel chromatography (0 to 100% ethyl acetate/hexanes) to give the desired product as a white solid (824 mg, 52%): 1H NMR (300 MHz, CDCl3) δ 9.09 (d, J=2.3 Hz, 1H), 8.71 (dd, J=4.9, 1.3 Hz, 1H), 8.25 (dt, J=8.2, 1.7 Hz, 1H), 7.41 (dd, J=7.9, 4.9 Hz, 1H), 4.48 (q, J=7.3 Hz, 2H), 1.46 (t, J=7.3 Hz, 3H); ESIMS m/z 315.0 (M+2).

後処理

  1. customwas transferred via canula into a −78° C.
  2. stirringThis mixture was stirred for 5 min
  3. customthe reaction vessel was removed from the cooling bath
  4. customThe reaction was quenched
  5. additionby pouring into a mixture of ether and water
  6. customThe layers were separated
  7. extractionthe aqueous layer was extracted twice with ethyl acetate
  8. dry with materialThe combined organics were dried over MgSO4
  9. filtrationfiltered
  10. customthe solvent was removed in vacuo

出典と根拠

ORDレコード
ord-922ebd249cd241afb6ffec5284141735
出典データセット
uspto-grants-2014_10
特許番号
US08853246B2

反応ノート

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