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Synlett
Volumn , Issue 10, 2007, Pages 1541-1544
Aza-Wittig reaction, carbodiimide-mediated ring closure, and enol-induced ring interconversion: A domino process for the synthesis of 4-methylene-4H-3,1- benzoxazines
Author keywords

Aza Wittig reaction; Heterocycles; Iminophosphoranes; Multicomponent reactions; Tandem reactions
Indexed keywords

4 METHYLENE 4H 3,1 BENZOXAZINE DERIVATIVE; ALKALOID DERIVATIVE; BENZOXAZINE DERIVATIVE; CARBENE; CYANAMIDE; ISOCYANIC ACID DERIVATIVE; PHOSPHORANE DERIVATIVE; RHOPALADIN D; TRIPHENYLPHOSPHINE; UNCLASSIFIED DRUG;
EID: 34347345096     PISSN: 09365214     EISSN: None     Source Type: Journal    
DOI: 10.1055/s-2007-982546     Document Type: Article
Times cited : (12)
References (30)
  • 5
    • 34347362628 scopus 로고    scopus 로고
    • Palacios, F.; Alonso, C.; Aparicio, D.; Rubiales, G.; de los Santos, J. M. Tetrahedron 2007, 63, 524.
    • (c) Palacios, F.; Alonso, C.; Aparicio, D.; Rubiales, G.; de los Santos, J. M. Tetrahedron 2007, 63, 524.
  • 9
    • 2442616727 scopus 로고    scopus 로고
    • and references cited therein
    • (d) Arques, A.; Molina, P. Curr. Org. Chem. 2004, 8, 827; and references cited therein.
    • (2004) Curr. Org. Chem , vol.8 , pp. 827
    • Arques, A.1    Molina, P.2
  • 16
    • 34347353853 scopus 로고    scopus 로고
    • N-(2-Acetylphenyl)-2, triphenylphosphoranylidene)amino]benzamide (4) To a solution of N-(2-acetylphenyl)-2-azidobenzamide (3, 3.5 g, 12.5 mmol) in dry CH2Cl2 (70 mL, PPh3 (3.6 g, 13.6 mmol) in CH2Cl2 (70 mL) was added dropwise at 0°C under N2. The resultant mixture was stirred at r.t. for 12 h. The solvent was removed under reduced pressure and the residue was recrystallized from CH2Cl2-n-hexane (1:1) to give 4 (6.3 g, 98% yield, Yellow prisms, mp 195-196°C. 1H NMR (400 MHz, CDCl3, δ, 2.22 (s, 3 H, CH3CO, 6.46 (dt, 1 H, J, 8.1, 1.0 Hz, H-6, 6.71 (ddd, 1 H, J, 7.2, 7.8, 1.0 Hz, H-4, 6.92 (ddd, 1 H, J, 7.2, 8.1, 2.2 Hz, H-5, 7.08 (ddd, 1 H, J, 7.9, 7.3, 1.1 Hz, H-4′, 7.34-7.39 (m, 6 H, Hm, 7.43-7.51 (m, 4 H, Hp and H-5′, 7.62 dd, 1 H, J, 7.9, 2.2 Hz, H-3
    • 2: C, 77.04; H, 5.25; N, 5.45. Found: C, 77.01; H, 5.20; N, 5.41.
  • 17
    • 34347340144 scopus 로고    scopus 로고
    • Preparation of 3-[2-(Methylene-4H-benzo[d][1,3]oxazine-2-yl)phenyl]urea 1-Substituted (7) To a solution of N-(2-acetylphenyl)-2-(triphenylphosphoranylidenamino)benzamide (4, 0.4 g, 0.78 mmol) in dry toluene (40 mL, the corresponding isocyanate (1.56 mmol) was added at r.t. under N2. The resulting mixture was warmed at reflux temperature for 6-12 h. After removal of the solvent by reduced pressure, the residue was recrystrallized in CH2Cl 2-n-hexane (1:1, 1-Ethyl-3-[2-(methylene-4 H-benzo[d][1,3]oxazine-2-yl)phenyl)urea (7a) Yield 85, 0.2 g, white prisms, mp 191-192°C. 1H NMR (400 MHz, DMSO-d 6, δ, 1.11 (t, 3 H, J, 7.2 Hz, CH 3CH2, 3.18 (q, 2 H, J, 7.2, 7.8 Hz, CH3CH2, 4.82 (d, 1 H, J, 2.9 Hz, CH2, 5.14 d, 1 H, J, 2.9 Hz, CH2
    • 3: C, 72.18; H, 5.26 N, 10.53. Found: C, 71.97; H, 5.01; N, 5.35.
  • 25
    • 34347363671 scopus 로고    scopus 로고
    • 2-(3-Indolecarbonyl)-5-(4-methoxyphenylimino)-4, 1-methoxymethyl-3- indolyl)methylidene]-5H-oxazole (11) To a solution of α-azidoamide 8 (0.2 g, 0.53 mmol) and 3-indolyloxalyl chloride (0.11 g, 0.53 mmol) in anhyd THF (20 mL, diphenylmethyl phosphine (0.16 g, 0.795 mmol) was added at r.t. under nitrogen. The mixture was stirred for 24 h, then warmed to reflux temperature, and Et3N (80 mg, 0.11 mL, 0.795 mmol) was added. After that, the mixture was stirred for 1 h, the solvent was eliminated under reduced pressure to give a residue which was purified by column chromatography on silica gel with EtOAc-n-hexane (6:4) as eluent to afford two fractions of the imino-oxazole 10 in 60 yield, corresponding to E (32 mg, 12, and Z (128 mg, 48, isomers, E)-2-(3-Indolecarbonyl)-5-(4-methoxyphenylimino, 4, 1-methoxymethyl-3-indolyl)methylidene]-5H-oxazole Rf=0.81
    • 4 (504.54): C, 71.42; H, 4.79; N, 11.10. Found: C, 71.51; H, 4.90; N, 10.97.

* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.