Reaktionsgleichung
NCC([O-])=O.[Na+].C(OC(=O)C)(=O)C.C([N:17]1[CH:21]=[C:20]2[CH2:22][CH:23]([NH:26]C(=O)C)[CH2:24][CH2:25][C:19]2=[CH:18]1)(=O)C>>[CH2:24]1[CH:23]([NH2:26])[CH2:22][C:20]2[C:19](=[CH:18][NH:17][CH:21]=2)[CH2:25]1Komponenten
Versuchsvorschrift
According to Reaction Scheme I, 4-acetamido cyclohexanone, prepared by the procedure of Fraser and Swingle, Can. J. Chem., 48, 2065 (1970) is reacted with the dimethylacetal of dimethylformamide to yield 2-dimethylaminomethylene-4-acetamidocyclohexanone (III). Reacting this compound with sodium glycinate followed by a ring closure reaction in the presence of acetic anhydride yields, when R3 is methyl, dl-2-acetyl-5-acetamido-4,5,6,7-tetrahydro-2H-benzo[c]-pyrrole (IV). Treatment of this latter compound with base gives dl-5-amino-4,5,6,7-tetrahydro-2H-benzo[c]pyrrole (V). This latter compound can be preferentially alkylated on the amino group at C-5 using a reductive alkylation procedure; i.e., reaction with an aldehyde (formaldehyde, acetaldehyde, acrolein, or propionaldehyde) in the presence of a strong organometallic reducing agent such as sodium cyanoborohydride. The dialkylated compound, for instance, dl-5-di(n-propyl)amino-4,5,6,7-tetrahydro-2H-benzo[c]pyrrole (VI) can also be alkylated on the pyrrole ring nitrogen under basic conditions using an alkyl halide R2X (methyl iodide, allyl chloride, ethyl bromide, or the like) to yield a dl-2-(C1 -C3 alkyl or allyl)-5 -disubstituted-amino-4,5,6,7-tetrahydro-2H-benzo[c]pyrrole of Formula VII.
Aufarbeitung
- customyields
Quellen und Nachweise
- ORD-Eintrag
- ord-b430971c264b45a48e5fdcde394ff82a
- Quelldatensatz
- uspto-grants-1980_11
- Patentnummer
- US04235776
Verknüpfte Notizen
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