4,7-Phenanthroline → 5-methoxy-4,7-phenanthroline
Reaction equation
[C:1]1(=[O:14])C2C(C3C(C=2)=CC=CC=3)=CN=N1.[CH:15]1[C:28]2[C:19](=[CH:20][CH:21]=[C:22]3[C:27]=2[CH:26]=[CH:25][CH:24]=[N:23]3)[N:18]=[CH:17][CH:16]=1>>[CH3:1][O:14][C:20]1[CH:21]=[C:22]2[C:27]([CH:26]=[CH:25][CH:24]=[N:23]2)=[C:28]2[C:19]=1[N:18]=[CH:17][CH:16]=[CH:15]2Participants
Procedure
Some phenanthrolines are very reluctant to undergo the usual basic oxidative rearrangement to the corresponding diazafluorenone. This is true of 4,7-phenanthroline, for instance. In this case, one uses 2-methoxyparaphenylenediamine in a double Skraup synthesis to produce the enolether, 5-methoxy-4,7-phenanthroline (150). Reaction of it with concentrated sulfuric acid and fuming nitric acid yields 4,7-phenanthrolin-5,6-quinone (151). The quinone undergoes oxidative rearrangement to produce 1,8-diazafluoren-9-one (152). Hydrazine reduction produces 1,8-diazafluorene (153) which is alkylated to the target compound, 9,9-bis(4-pyridinylmethyl)-1,8-diazafluorene (154). Other diazafluorenes produced by this method include 1,5-diazafluorene, (Scheme 67, 157), 1,6-diazafluorene, 2,5-diazafluorene, 3,5-diazafluorene, and 4,5-diazafluorene. See references for Scheme 64 and: French patent 1,382,542; French patent 1,369,626, U.S. Pat. No. 2,640,830, Swiss patent 275,433. ##STR87##
Workup
- customIn this case, one uses 2-methoxyparaphenylenediamine in a double Skraup synthesis
Sources & evidence
- ORD record
- ord-286a764f08be4f30a9da6c15e4871e11
- Source dataset
- uspto-grants-1994_04
- Patent number
- US05300642
Reaction notes
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