Hydrochloric Acid → 4-[4-(4-Oxopiperidin-1-yl)phenyl]piperazine-1-carboxylic acid benzyl ester

HRID 1816744Notes

Reaction equation

[CH2:1]([O:8][C:9]([N:11]1[CH2:16][CH2:15][N:14]([C:17]2[CH:22]=[CH:21][C:20]([N:23]3[CH2:32][CH2:31][C:26]4(OCC[O:27]4)[CH2:25][CH2:24]3)=[CH:19][CH:18]=2)[CH2:13][CH2:12]1)=[O:10])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.Cl.O.[OH-].[Na+]>O1CCOCC1>[CH2:1]([O:8][C:9]([N:11]1[CH2:16][CH2:15][N:14]([C:17]2[CH:22]=[CH:21][C:20]([N:23]3[CH2:32][CH2:31][C:26](=[O:27])[CH2:25][CH2:24]3)=[CH:19][CH:18]=2)[CH2:13][CH2:12]1)=[O:10])[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

Conditions

Temperature: 90 °C

Procedure

To a solution of 4-[4-(1,4-dioxa-8-azaspiro[4.5]decan-8-yl)phenyl]piperazine-1-carboxylic acid benzyl ester (30 g) in 1,4-dioxane (450 ml) was added 1N-hydrochloric acid (240 ml) at ambient temperature, and the mixture was stirred for 7 hours at 90° C. The reaction mixture was poured into water. The mixture was adjusted to pH 10-12 with 1N-sodium hydroxide (480 ml), and extracted with ethyl acetate. The organic layer was washed with water, brine, and dried, and evaporated under reduced pressure. The residue was chromatographed on a column of silica gel eluting with dichloromethane/methyl alcohol (50:1) to give 4-[4-(4-oxopiperidin-1-yl)phenyl]piperazine-1-carboxylic acid benzyl ester (21.22 g).

Workup

extractionextracted with ethyl acetate
washThe organic layer was washed with water, brine
customdried
customevaporated under reduced pressure
customThe residue was chromatographed on a column of silica gel eluting with dichloromethane/methyl alcohol (50:1)

Sources & evidence

ORD record: ord-66daaec9c03d40fdaa46ba3290aa9f24
Source dataset: uspto-grants-2005_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06884868B1

Reaction notes

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