2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → 3-Ethyl 5-methyl 2-amino-4-(chroman-6-yl)-6-methylpyridine-3,5-dicarboxylate

HRID 1912542Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1912542
[NH2:1][C:2]1[NH:3][C:4]([CH3:27])=[C:5]([C:23]([O:25][CH3:26])=[O:24])[CH:6]([C:13]2[CH:14]=[C:15]3[C:20](=[CH:21][CH:22]=2)[O:19][CH2:18][CH2:17][CH2:16]3)[C:7]=1[C:8]([O:10][CH2:11][CH3:12])=[O:9].C(C1C(=O)C(Cl)=C(Cl)C(=O)C=1C#N)#N>ClCCl>[NH2:1][C:2]1[C:7]([C:8]([O:10][CH2:11][CH3:12])=[O:9])=[C:6]([C:13]2[CH:14]=[C:15]3[C:20](=[CH:21][CH:22]=2)[O:19][CH2:18][CH2:17][CH2:16]3)[C:5]([C:23]([O:25][CH3:26])=[O:24])=[C:4]([CH3:27])[N:3]=1

Komponenten

4

Versuchsvorschrift

A mixture of methyl 2-(chroman-6-ylmethylene)-3-oxobutanoate (8.27 g, 31.8 mmol), ethyl 3,3-diaminoacrylate, hydrochloride (5.29 g, 31.8 mmol) and 4-methylmorpholine (3.49 mL, 31.8 mmol) in Isopropanol (76.0 mL) was heated to 90° C. overnight. The mixture was concentrated, dissolved in ethyl acetate, washed with brine, dried over sodium sulfate, filtered and concentrated to provide crude 3-ethyl 5-methyl 2-amino-4-(chroman-6-yl)-6-methyl-1,4-dihydropyridine-3,5-dicarboxylate which was used without further purification. 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 7.00-6.87 (m, 3 H), 6.64-6.58 (m, 1 H), 6.20 (br. s., 2 H), 4.83-4.77 (m, 1 H), 4.15-4.05 (m, 4 H), 3.71-3.63 (m, 3 H), 2.71 (t, J=6.3 Hz, 2 H), 2.27-2.16 (m, 3 H), 1.99-1.93 (m, 2 H), 1.27-1.22 (m, 3 H); LC/MS (m/z) ES+=373.3 (M+1). A solution of crude 3-ethyl 5-methyl 2-amino-4-(chroman-6-yl)-6-methyl-1,4-dihydropyridine-3,5-dicarboxylate in dichloromethane (DCM) (216 mL) was treated with DDQ (7.22 g, 31.8 mmol) and then stirred at ambient temperature (mixture turned dark within one minute). The mixture was filtered over Celite™. The filtrate was diluted with saturated sodium bicarbonate and the layers were separated. The aqueous phase was extracted with DCM. The combined extracts were washed with brine, dried over sodium sulfate, filtered and concentrated. The residue was purified on silica gel (0-100% hexane/EA) to afford 3-ethyl 5-methyl 2-amino-4-(chroman-6-yl)-6-methylpyridine-3,5-dicarboxylate (7.64 g, 20.63 mmol, 64.9% yield) as a brown solid. 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 6.86 (d, 1 H), 6.81 (s, 1 H), 6.73 (d, J=8.4 Hz, 1 H), 6.23-6.02 (m, 2 H), 4.17 (t, J=4.7 Hz, 2 H), 3.99-3.77 (m, 2 H), 3.52-3.43 (m, 3 H), 2.73 (br. s., 2H), 2.45-2.35 (m, 3 H), 1.98 (br. s., 2 H), 0.83-0.67 (m, 3 H); LC/MS (m/z) ES+=371.3 (M+1).

Aufarbeitung

  1. customwas used without further purification
  2. filtrationThe mixture was filtered over Celite™
  3. additionThe filtrate was diluted with saturated sodium bicarbonate
  4. customthe layers were separated
  5. extractionThe aqueous phase was extracted with DCM
  6. washThe combined extracts were washed with brine
  7. dry with materialdried over sodium sulfate
  8. filtrationfiltered
  9. concentrationconcentrated
  10. customThe residue was purified on silica gel (0-100% hexane/EA)

Quellen und Nachweise

ORD-Eintrag
ord-2b402777a9794ad5a1f7a344d9bf953e
Quelldatensatz
uspto-grants-2013_12
Patentnummer
US08609653B2

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