Ethyl isocyanate → 2-(3-Ethyl-ureido)-5-pyridin-3-yl-benzothiazole-7-carboxylic acid methyl ester

HRID 1941953Notes

Reaction equation

[CH3:1][O:2][C:3]([C:5]1[C:13]2[S:12][C:11]([NH2:14])=[N:10][C:9]=2[CH:8]=[C:7]([C:15]2[CH:16]=[N:17][CH:18]=[CH:19][CH:20]=2)[CH:6]=1)=[O:4].[CH2:21]([N:23]=[C:24]=[O:25])[CH3:22]>O1CCOCC1>[CH3:1][O:2][C:3]([C:5]1[C:13]2[S:12][C:11]([NH:14][C:24]([NH:23][CH2:21][CH3:22])=[O:25])=[N:10][C:9]=2[CH:8]=[C:7]([C:15]2[CH:16]=[N:17][CH:18]=[CH:19][CH:20]=2)[CH:6]=1)=[O:4]

Participants

Conditions

Temperature: 100 °C

Procedure

A stirred mixture of 2-Amino-5-pyridin-3-yl-benzothiazole-7-carboxylic acid methyl ester (125 mg, 0.439 mmol), ethyl isocyanate (0.21 ml, 2.187 mmol) and dibutyltindiacetate (12 drops) in anhydrous 1,4-dioxane (10 ml) was heated in a sealed vessel at 100° C. for 16 h. After cooling to ambient temperature, the solvent was removed in vacuo to give 2-(3-Ethyl-ureido)-5-pyridin-3-yl-benzothiazole-7-carboxylic acid methyl ester which was used without further purification. A stirred mixture of 2-(3-Ethyl-ureido)-5-pyridin-3-yl-benzothiazole-7-carboxylic acid methyl ester (78 mg, 0.22 mmol) and aqueous ethylamine solution (70% w/v, 3 ml) was heated by microwave irradiation in a CEM Discover reactor at 100° C. for 1 h. The reaction mixture was purified by Preparative HPLC to provide the 2-(3-Ethyl-ureido)-5-pyridin-3-yl-benzothiazole-7-carboxylic acid ethylamide as a white solid (8.7 mg, 5%).

Workup

temperatureAfter cooling to ambient temperature
customthe solvent was removed in vacuo

Sources & evidence

ORD record: ord-07efc1b94d594baf9889a1e5727b89fc
Source dataset: uspto-grants-2013_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08389516B2

Reaction notes

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