Sodium Carbonate → 2-(2-Aminopyridin-3-yl)-1-benzothiophene-5-carboxylic acid

HRID 2205562Notes

Reaction equation

[NH2:1][C:2]1[C:7](I)=[CH:6][CH:5]=[CH:4][N:3]=1.OB(O)[C:11]1[S:12][C:13]2[CH:19]=[CH:18][C:17]([C:20]([OH:22])=[O:21])=[CH:16][C:14]=2[CH:15]=1.C(=O)([O-])[O-].[Na+].[Na+].C1C=CC(P(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>O1CCOCC1.CC([O-])=O.CC([O-])=O.[Pd+2]>[NH2:1][C:2]1[C:7]([C:11]2[S:12][C:13]3[CH:19]=[CH:18][C:17]([C:20]([OH:22])=[O:21])=[CH:16][C:14]=3[CH:15]=2)=[CH:6][CH:5]=[CH:4][N:3]=1

Participants

Conditions

Temperature: 50 °C

Procedure

To the degassed mixture of 2-amino-3-iodpyridine (1.12 g, 5.09 mmol, 1 eq), 2-(dihydroxyboryl)-1-benzothiophene-5-carboxylic acid, [2-(dihydroxyboryl)-1-benzothiophene-5-carboxylic acid (1.3 g, 1.15 eq)], and aqueous sodium carbonate (2M, 7.6 mL, 3 eq) in dioxane (10 mL) was added Ph3P (267 mg, 0.2 eq) and Pd(OAc)2 (114.3 mg, 0.1 eq). The mixture was heated to 50° C. with vigorous stirring for 30 minutes. The yellow mixture was then partitioned between aq NH4Cl and MeOH—CHCl3 (1:5). Some solids precipitation was observed. After the pH was carefully adjusted to around 6, the whole mixture was filtered through a Buchner funnel to obtain a yellow solid. The solid was further triturated with MeOH/H2O to give 2-(2-aminopyridin-3-yl)-1-benzothiophene-5-carboxylic acid as a white-off solid in amount of 1.18 g after dried in vacuo (86%).

Workup

customThe yellow mixture was then partitioned between aq NH4Cl and MeOH—CHCl3 (1:5)
customSome solids precipitation
filtrationthe whole mixture was filtered through a Buchner funnel
customto obtain a yellow solid
customThe solid was further triturated with MeOH/H2O

Sources & evidence

ORD record: ord-d9106467c57e4d8a89377d547bd9222a
Source dataset: uspto-grants-2016_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09371314B2

Reaction notes

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