4,5-Difluoro-2-nitroaniline → 6,7-Difluoro-1,2-dihydroquinoxalin-2-one

HRID 373773노트

반응식

HRID 373773 반응식
[F:1][C:2]1[C:8]([F:9])=[CH:7][C:5]([NH2:6])=[C:4]([N+:10]([O-])=O)[CH:3]=1.[H][H].O.[C:16](O)(=O)[CH:17]=[O:18]>C(O)C.[Pd].O>[F:1][C:2]1[CH:3]=[C:4]2[C:5](=[CH:7][C:8]=1[F:9])[NH:6][C:17](=[O:18])[CH:16]=[N:10]2

참가 물질

7

반응물 3

HCID 1571514,5-Difluoro-2-nitroanilineHCID 15620607Glyoxylic acid, monohydrateHCID 178418361HCID 178418361, 화합물

생성물 1

HCID 63243396,7-Difluoro-1,2-dihydroquinoxalin-2-one수율 55%

시약·촉매·용매 3

HCID 23938Palladium촉매HCID 702Ethanol용매HCID 962Water용매2회

실험 절차

4,5-difluoro-2-nitroaniline (2.17 g, 12.5 mmol) was dissolved in 55 ml of ethanol and 250 mg of 10% palladium on carbon was added. The mixture was hydrogenated until the theoretical amount of hydrogen had been absorbed, using a low pressure hydrogenation apparatus. The catalyst was filtered off and the filtrate, containing 4,5-difluoro-o-phenylenediamine, was kept under a nitrogen atmosphere at 0° C. followed by addition of a solution of glyoxylic acid hydrate (1.28 g, 13.7 mmol) in water (3 ml). When the addition was complete the reaction temperature was allowed to reach room temperature during 2 h and 30 ml of water was added. The precipitate was filtered off and dissolved in 60 ml of 5% NaOH solution at 50° C. followed by addition of activated carbon. The mixture was filtered and the filtrate was acidified (pH=1) by addition of concentrated hydrochloric acid. The pinky precipitate was filtered off, washed with water and dried to afford 1.25 g (55 %) of 6,7-difluoroquinoxalin-2(1H)-one melting at 284°-85° C. 1H-NMR (DMSO-d6): 7.27 (m, 1H), 7.95 (m, 1H), 8.20 (s, 1H), 12.55 (s,1H).

후처리

  1. customhad been absorbed
  2. filtrationThe catalyst was filtered off
  3. additionthe filtrate, containing 4,5-difluoro-o-phenylenediamine
  4. customwas kept under a nitrogen atmosphere at 0° C.
  5. additionWhen the addition
  6. filtrationThe precipitate was filtered off
  7. dissolutiondissolved in 60 ml of 5% NaOH solution at 50° C.
  8. additionfollowed by addition of activated carbon
  9. filtrationThe mixture was filtered
  10. additionby addition of concentrated hydrochloric acid
  11. filtrationThe pinky precipitate was filtered off
  12. washwashed with water
  13. customdried

출처 및 근거

ORD 기록
ord-9b6db4f50a4640269a0d75c5d9edd938
출처 데이터셋
uspto-grants-1992_11
특허 번호
US05166155

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