Ethyl orthoformate → 4-(4-Cyano-2-methoxyphenyl)-5-ethoxy-2,7-dimethyl-1,4-dihydro-1,6-naphthyridine-3-carbonitrile

HRID 1951424Notes

Reaction equation

[C:1]([C:3]1[CH:8]=[CH:7][C:6]([CH:9]2[C:18]3[C:17](=[O:19])[NH:16][C:15]([CH3:20])=[CH:14][C:13]=3[NH:12][C:11]([CH3:21])=[C:10]2[C:22]#[N:23])=[C:5]([O:24][CH3:25])[CH:4]=1)#[N:2].C(OCC)(OCC)O[CH2:28][CH3:29]>S(=O)(=O)(O)O>[C:1]([C:3]1[CH:8]=[CH:7][C:6]([CH:9]2[C:18]3[C:13](=[CH:14][C:15]([CH3:20])=[N:16][C:17]=3[O:19][CH2:28][CH3:29])[NH:12][C:11]([CH3:21])=[C:10]2[C:22]#[N:23])=[C:5]([O:24][CH3:25])[CH:4]=1)#[N:2]

Participants

Conditions

Temperature: 130 °C

Procedure

1920 mg (5.77 mmol) of 4-(4-cyano-2-methoxyphenyl)-2,7-dimethyl-5-oxo-1,4,5,6-tetrahydro-1,6-naphthyridine-3-carbonitrile are suspended in 40 ml (240 mmol) of anhydrous triethyl orthoformate. The reaction mixture is heated to 130° C. Then 10 drops of concentrated sulfuric acid are added each hour. After complete reaction has been detected (analytical HPLC; reaction time about 36 h), the reaction mixture is cooled to room temperature, and the volatile components are removed in a rotary evaporator. The crude product is purified by column chromatography (silica gel; mobile phase: cyclohexane/ethyl acetate 1:1). The product obtained in this way is crystallized from ethyl acetate. 451 mg (22% of theory) of the title compound are obtained as a white solid.

Workup

customAfter complete reaction
custom(analytical HPLC; reaction time about 36 h)
temperaturethe reaction mixture is cooled to room temperature
customthe volatile components are removed in a rotary evaporator
customThe crude product is purified by column chromatography (silica gel; mobile phase: cyclohexane/ethyl acetate 1:1)
customThe product obtained in this way
customis crystallized from ethyl acetate

Sources & evidence

ORD record: ord-c20a093fa2fe43bcb7979604b7c3124c
Source dataset: uspto-grants-2013_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08404709B2

Reaction notes

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