3-Methoxybenzaldehyde → Ethyl 4-(3-methoxyphenyl)piperidine-3-carboxylate

HRID 67797

Reaktionsgleichung

Reaktionsgleichung von HRID 67797
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:9]2[CH2:14][CH2:13][N:12](C)[CH2:11][CH:10]2[C:16]([O:18][CH2:19][CH3:20])=[O:17])[CH:6]=[CH:7][CH:8]=1.COC1C=C(C=CC=1)C=O.F[B-](F)(F)F.C[O+](C)C.[BH4-].[Na+]>C(O)C>[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:9]2[CH2:14][CH2:13][NH:12][CH2:11][CH:10]2[C:16]([O:18][CH2:19][CH3:20])=[O:17])[CH:6]=[CH:7][CH:8]=1

Komponenten

6

Versuchsvorschrift

In the preparation of ethyl 4-(3'-methoxyphenyl)-1-methylpiperidine-3-carboxylate (23), a synthesis of 4-aryl 2-unsubstituted nipecotic acids was developed. In this process modifying a known procedure [cf. C. F. Koelsch, J. of the Am. Chem. Soc., 65:2459 (1943)], 3-methoxybenzaldehyde (18) was converted to the amide ester, ethyl 4-(3'-methoxyphenyl)-2-piperidone-5-carboxylate (21), via standard procedures. Selective reduction of the amide function of 21 was achieved by reaction with trimethyloxonium fluoroborate followed immediately by treatment with NaBH4 in ethanol to yield amino ester, ethyl 4-(3'-methoxyphenyl)piperidine-3-carboxylate (22). Reductive methylation gave the required nipecotate 23 in 48% overall yield from 3-methoxybenzaldehyde (18).

Quellen und Nachweise

ORD-Eintrag
ord-1f31d8078a304ae085e9bcac7846089b
Quelldatensatz
uspto-grants-1982_08
Patentnummer
US04346224

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