Diethyl Oxalate → 3,4,4a,5,6,7-Hexahydropyrazino[1,2-a][1]benzazepine-1,2-dione

HRID 80531Notes

Reaction equation

HRID 80531 reaction equation
[NH:1]1[C:7]2[CH:8]=[CH:9][CH:10]=[CH:11][C:6]=2[CH2:5][CH2:4][CH2:3][CH:2]1[CH2:12][NH2:13].[C:14](OCC)(=[O:20])[C:15](OCC)=[O:16]>>[C:14]1(=[O:20])[N:1]2[C:7]3[CH:8]=[CH:9][CH:10]=[CH:11][C:6]=3[CH2:5][CH2:4][CH2:3][CH:2]2[CH2:12][NH:13][C:15]1=[O:16]

Participants

3

Reactant 2

HCID 7268Diethyl OxalateHCID 13842540(2,3,4,5-tetrahydro-1H-1-benzazepin-2-yl)methanamine

Product 1

HCID 667697593,4,4a,5,6,7-Hexahydropyrazino[1,2-a][1]benzazepine-1,2-dione

Procedure

A solution of Example 182E (0.282 g, 1.600 mmol) in diethyl oxalate (1.518 mL, 11.20 mmol) was heated at 140° C. for 1 hour and then at 180° C. for 2 hours. The crude mixture was purified by silica gel chromatography (Analogix IntelliFlash™ 280, SF24-40) eluting with dichloromethane, then with 2% methanol/dichloromethane, and then with 10% methanol/dichloromethane to obtain the title compound. 1H NMR (400 MHz, DMSO-d6) δ ppm 8.66 (s, 1H), 7.37-7.17 (m, 4H), 3.91 (dd, J=12.8, 4.2, 1H), 3.49 (d, J=11.4, 1H), 3.19-3.13 (m, 1H), 2.71 (dd, J=18.6, 12.5, 1H), 2.56 (m, 1H), 2.02 (m, 2H), 1.86 (m, 1H), 1.42 (m, 1H); MS (ESI+) m/z 248.2 (M+NH4).

Workup

  1. customThe crude mixture was purified by silica gel chromatography (Analogix IntelliFlash™ 280, SF24-40)
  2. washeluting with dichloromethane

Sources & evidence

ORD record
ord-3a24ccdcaf3c43d3a88a05ba876c27b1
Source dataset
uspto-grants-2014_09
Patent number
US08846663B2

Reaction notes

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