2-[2-[(Ethoxycarbonyl)amino]ethyl]-6-methoxyphenyl ethyl carbonate → Ethyl 6-methoxy-1-oxo-1,2,3,4-tetrahydroisoquinolin-5-yl carbonate

HRID 717364Notes

Reaction equation

[C:1](=[O:22])([O:19][CH2:20][CH3:21])[O:2][C:3]1[C:8]([O:9][CH3:10])=[CH:7][CH:6]=[CH:5][C:4]=1[CH2:11][CH2:12][NH:13][C:14](OCC)=[O:15]>C(OCC)(=O)C.O>[C:1](=[O:22])([O:2][C:3]1[C:8]([O:9][CH3:10])=[CH:7][CH:6]=[C:5]2[C:4]=1[CH2:11][CH2:12][NH:13][C:14]2=[O:15])[O:19][CH2:20][CH3:21]

Participants

Conditions

Temperature: 142.5 °C

Procedure

Into a 500-mL 3-necked round-bottom flask purged and maintained with an inert atmosphere of nitrogen, was placed polyphosphoric acid (PPA, 150 g). This was followed by the addition of 2-[2-[(ethoxycarbonyl)amino]ethyl]-6-methoxyphenyl ethyl carbonate (20 g, 64.24 mmol, 1.00 equiv) at 145° C. The resulting solution was stirred for 20 min at 140-145° C. The reaction mixture was cooled to room temperature with a water/ice bath. The resulting solution was diluted with 500 mL of ethyl acetate and 500 mL of water. The resulting mixture was washed with 3×300 mL of water. The mixture was dried over anhydrous sodium sulfate and concentrated under vacuum. The residue was applied onto a silica gel column with ethyl acetate/petroleum ether (1:1). This resulted in 1.5 g (9%) of ethyl 6-methoxy-1-oxo-1,2,3,4-tetrahydroisoquinolin-5-yl carbonate as a gray solid. MS (ESI) m/z 266 ([M+H]+).

Workup

customInto a 500-mL 3-necked round-bottom flask purged
temperaturemaintained with an inert atmosphere of nitrogen
temperatureThe reaction mixture was cooled to room temperature with a water/ice bath
washThe resulting mixture was washed with 3×300 mL of water
dry with materialThe mixture was dried over anhydrous sodium sulfate
concentrationconcentrated under vacuum
customThis resulted in 1.5 g (9%) of ethyl 6-methoxy-1-oxo-1,2,3,4-tetrahydroisoquinolin-5-yl carbonate as a gray solid

Sources & evidence

ORD record: ord-ccca1dc79d4045b9bb751f8226f9a85e
Source dataset: uspto-grants-2015_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09193707B2

Reaction notes

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