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

HRID 533323노트

반응식

HRID 533323 반응식
[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]

참가 물질

5

반응물 3

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

생성물 1

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

시약·촉매·용매 1

HCID 8028Tetrahydrofuran용매2회

실험 절차

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).

후처리

  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

출처 및 근거

ORD 기록
ord-922ebd249cd241afb6ffec5284141735
출처 데이터셋
uspto-grants-2014_10
특허 번호
US08853246B2

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