Sulfuric Acid → Methyl 5-(piperazin-1-yl)benzofuran-2-carboxylate

HRID 628794Notes

Reaction equation

C1(S([N:10]2[CH2:15][CH2:14][N:13]([C:16]3[CH:17]=[CH:18][C:19]4[O:23][C:22]([C:24]([O:26][CH3:27])=[O:25])=[CH:21][C:20]=4[CH:28]=3)[CH2:12][CH2:11]2)(=O)=O)C=CC=CC=1.S(=O)(=O)(O)O.[OH-].[NH4+]>>[N:13]1([C:16]2[CH:17]=[CH:18][C:19]3[O:23][C:22]([C:24]([O:26][CH3:27])=[O:25])=[CH:21][C:20]=3[CH:28]=2)[CH2:12][CH2:11][NH:10][CH2:15][CH2:14]1

Participants

Reactant 3

HCID 1118Sulfuric Acid

HCID 14923Ammonium Hydroxide

HCID 90022245Methyl 5[4-(benzenesulfonyl)-1-piperazinyl]benzofuran-2-carboxylate

Product 1

HCID 77231352Methyl 5-(piperazin-1-yl)benzofuran-2-carboxylateYield 100%

Conditions

Temperature: 100 °C

Procedure

Methyl 5[4-(benzenesulfonyl)-1-piperazinyl]benzofuran-2-carboxylate (10 g) was added to sulfuric acid (25 g) at 25-30° C. and the mixture was heated to 98-102° C., followed by stirring for 15 minutes at the same temperature. The reaction mass was cooled to 25-30° C. and then poured into ice cold water (80 ml). The pH of the resulting aqueous layer was adjusted to 9-10 with ammonium hydroxide solution, followed by extracting with ethyl acetate (3×200 ml) and then distilling off the solvent under vacuum to produce 6.5 g of methyl 5-(1-piperazinyl)benzofuran-2-carboxylate (Yield: 96%).

Workup

temperatureThe reaction mass was cooled to 25-30° C.
extractionby extracting with ethyl acetate (3×200 ml)
distillationdistilling off the solvent under vacuum

Sources & evidence

ORD record: ord-f6920cd9b88346f5a94f1070ce9bcda6
Source dataset: uspto-grants-2016_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09315456B2

Reaction notes

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