ortho-aminophenylbenzoxazole → HCID 4327811, compound

HRID 1439844Notes

Reaction equation

HRID 1439844 reaction equation
[N+:1]([C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][C:5]=1[C:10]1[O:11][C:12]2[CH:18]=[CH:17][CH:16]=[CH:15][C:13]=2[N:14]=1)([O-])=O.NC1C=CC=C[C:21]=1[C:26]1[O:27]C2C=CC=CC=2N=1>C(Cl)Cl.C(O)C.O=[Pt]=O>[O:11]1[C:12]2[CH:18]=[CH:17][CH:16]=[CH:15][C:13]=2[N:14]=[C:10]1[C:5]1[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=1[NH:1][C:26](=[O:27])[CH3:21]

Participants

6

Reactant 2

HCID 4602658ortho-aminophenylbenzoxazoleHCID 152078672-(2-Nitrophenyl)-1,3-benzoxazole

Product 1

HCID 4327811HCID 4327811, compound

Reagents, catalysts & solvents 3

HCID 345198Adams' catalystCatalystHCID 702EthanolSolventHCID 6344DichloromethaneSolvent

Procedure

The compound was prepared in a multistep synthesis employing Scheme 3, as described: A suspension of 2-aminophenol (5.0 g, 45.81 mmol) and 2-nitrobenzaldehyde (6.92 g, 45.81 mmol) in cyclohexane (200 mL) was heated to reflux using a Dean-Stark apparatus to remove water for 5 h. The reaction mixture was concentrated in vacuo to yield bright yellow crystals of the corresponding imine (10.71 g, 97% yield). To a solution of this imine (7.88 g, 32.56 mmol) in CH2Cl2 (200 mL) was added Ag2O (9.05 g, 39.07 mmol) and the reaction mixture was allowed to stir at RT overnight. The solvent was removed in vacuo to yield a solid shown to be the 2-(2-nitrophenyl) benzoxazole. This product was then suspended in ethanol (200 mL) with PtO2 (0.3 g) and charged with H2 (60 psi). The reaction mixture was allowed to shake on a Parr apparatus for 3 h. This was filtered through celite and the filtrate was removed in vacuo to yield a yellow solid. 1H NMR showed this to be the desired 2-(2-aminophenyl) benzoxazole, 3.85 g. This was acetylated according to General Procedure A and purified by recrystallization from cyclohexane/ethyl acetate, m.p. 125°-128° C.; 1H NMR (300 MHz, DMSO-d6) δ11.48 (s, 1H), 8.54 (d, J=9 Hz, 1H), 8.13 (dd, J=1.5, 9 Hz, 1H), 7.80-7.75 (m, 2H), 7.57 (m, 1H), 7.45 (m, 2H), 7.25 (t, J=9 Hz, 1H), 2.23 (s, 3H); 13C NMR (75 MHz, DMSO-d6) δ5 168.79, 161.46, 148.92, 140.39, 138.59, 132.89, 128.62, 126.18, 125.28, 123.37, 120.29, 119.83, 113.05, 111.07, 25.15; IR (KBr) 3270, 1685, 1540, 1240, 750 cm-1 ; MS (DCI) m/e MH+ =253; Analysis calc' d for C15H12N2O2 : C, 71.42; H, 4.79; N, 11.10; found: C, 71.24; H, 5.14;N, 10.76.

Workup

  1. customThe solvent was removed in vacuo
  2. customto yield a solid
  3. additioncharged with H2 (60 psi)
  4. waitto shake on a Parr apparatus for 3 h
  5. filtrationThis was filtered through celite
  6. customthe filtrate was removed in vacuo
  7. customto yield a yellow solid
  8. custompurified by recrystallization from cyclohexane/ethyl acetate, m.p. 125°-128° C.

Sources & evidence

ORD record
ord-082773829413432c8c4672d7a7a1d0ea
Source dataset
uspto-grants-1996_03
Patent number
US05496826

Reaction notes

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