Dimethylformamide → n-Cyclobutyl-1'-methyl-2'-oxo-1',2,2',3-tetrahydrospiro[furo[2,3-g][1,4]benzodioxine-8,3'-indole]-4'-carboxamide
Reaction equation
[CH3:1][N:2]1[C:10]2[CH:9]=[CH:8][CH:7]=[C:6]([C:11](OC3C=CC=CC=3)=[O:12])[C:5]=2[C:4]2([C:31]3[C:22](=[CH:23][C:24]4[O:29][CH2:28][CH2:27][O:26][C:25]=4[CH:30]=3)[O:21][CH2:20]2)[C:3]1=[O:32].Cl.[CH:34]1([NH2:38])[CH2:37][CH2:36][CH2:35]1.C(=O)([O-])[O-].[K+].[K+].CN(C)C=O>O>[CH:34]1([NH:38][C:11]([C:6]2[C:5]3[C:4]4([C:31]5[C:22](=[CH:23][C:24]6[O:29][CH2:28][CH2:27][O:26][C:25]=6[CH:30]=5)[O:21][CH2:20]4)[C:3](=[O:32])[N:2]([CH3:1])[C:10]=3[CH:9]=[CH:8][CH:7]=2)=[O:12])[CH2:37][CH2:36][CH2:35]1Participants
Reactant 4
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 110 °C
Procedure
Phenyl 1′-methyl-2′-oxo-1′,2,2′,3-tetrahydrospiro[furo[2,3-g][1,4]benzodioxine-8,3′-indole]-4′-carboxylate (0.30 g, 0.70 mmol), cyclobutylamine hydrochloride (0.23 g, 2.1 mmol), potassium carbonate (0.39 g, 2.8 mmol) and N,N-dimethylformamide (3.0 mL) were added to a microwave reaction vessel. The reaction was heated at 110° C. for 1 h in a microwave reactor, allowed to cool to ambient temperature, poured into water (25 mL) and extracted with ethyl acetate (3×50 mL). The combined organic extracts were washed with 1 M hydrochloric acid (50 mL) and brine (50 mL), dried over magnesium sulfate, filtered and concentrated in vacuo. The residue was purified by column chromatography and eluted with a 20% to 100% gradient of ethyl acetate in hexanes followed by recrystallization from dichloromethane/diethyl ether to afford N-cyclobutyl-1′-methyl-2′-oxo-1′,2,2′,3-tetrahydrospiro[furo[2,3-g][1,4]benzodioxine-8,3′-indole]-4′-carboxamide (0.045 g, 17%) as a colorless solid: mp 128-129° C. (dichloromethane/diethyl ether); 1H NMR (300 MHz, CDCl3) δ 7.41-7.33 (m, 1H), 7.26-7.21 (m, 1H), 6.97-6.93 (m, 1H), 6.51 (s, 1H), 6.20 (s, 1H), 5.46 (d, J=6.65 Hz, 1H), 4.96-4.81 (m, 2H), 4.35-4.01 (m, 5H), 3.25 (s, 3H), 2.27-2.09 (m, 2H), 1.70-1.40 (m, 4H); MS (ES+) m/z 407.0 (M+1). N,N,1′-trimethyl-2′-oxo-1′,2,2′,3-tetrahydrospiro[furo[2,3-g][1,4]benzodioxine-8,3′-indole]-4′-carboxamide (0.12 g, 37%) was isolated as a byproduct from the synthesis of N-cyclobutyl-1′-methyl-2′-oxo-1′,2,2′,3-tetrahydrospiro[furo[2,3-g][1,4]benzodioxine-8,3′-indole]-4′-carboxamide, obtained as colorless solid: mp 218-221° C. (dichloromethane/diethyl ether); 1H NMR (300 MHz, CDCl3) δ 7.32 (dd, J=7.8, 7.8 Hz, 1H), 6.91-6.84 (m, 2H), 6.44 (s, 1H), 6.22 (s, 1H), 5.05 (d, J=8.8 Hz, 1H), 4.79 (d, J=8.8 Hz, 1H), 4.20-4.04 (m, 4H), 3.28 (s, 3H), 2.79 (s, 3H), 2.19 (s, 3H); MS (ES+) m/z 381.0 (M+1).
Workup
- temperatureto cool to ambient temperature
- extractionextracted with ethyl acetate (3×50 mL)
- washThe combined organic extracts were washed with 1 M hydrochloric acid (50 mL) and brine (50 mL)
- dry with materialdried over magnesium sulfate
- filtrationfiltered
- concentrationconcentrated in vacuo
- customThe residue was purified by column chromatography
- washeluted with a 20% to 100% gradient of ethyl acetate in hexanes
- customfollowed by recrystallization from dichloromethane/diethyl ether
Sources & evidence
- ORD record
- ord-9750769df49b454f8eb514c651c61de7
- Source dataset
- uspto-grants-2014_12
- Patent number
- US08916580B2
Reaction notes
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