Selenium Dioxide → 4-Chloro-9H-dipyrido[2,3-b;4',3'-d]pyrrole-6-carboxylic acid methyl ester

HRID 60256Notes

Reaction equation

[CH3:1][O:2][C:3]([CH:5]1[NH:13][CH2:12][C:11]2[NH:10][C:9]3[N:14]=[CH:15][CH:16]=[C:17]([Cl:18])[C:8]=3[C:7]=2[CH2:6]1)=[O:4].[Se](=O)=O>O1CCOCC1>[CH3:1][O:2][C:3]([C:5]1[N:13]=[CH:12][C:11]2[NH:10][C:9]3[N:14]=[CH:15][CH:16]=[C:17]([Cl:18])[C:8]=3[C:7]=2[CH:6]=1)=[O:4]

Participants

Conditions

Temperature: 100 °C

Procedure

A mixture of 4-chloro-6,7,8,9-tetrahydro-5H-dipyrido[2,3-b;4′,3′-d]pyrrole-6-carboxylic acid methyl ester (2.1 g, 7.9 mmol) and selenium dioxide (1.20 g, 11.1 mol) in 1,4-dioxane (50 mL) was heated at 100° C. for 3.5 hours. The resulting grey slurry was filtered whilst hot through a pad of celite and the pad washed with hot THF and 25% methanol in dichloromethane. The combined filtrate was concentrated in-vacuo and the resultant residue triturated with methanol (10 mL). The resultant solid was collected by filtration and left to air dry to afford the title compound as an off white solid (1.03 g, 48%). 1H NMR (400 MHz, DMSO-d6): 13.02 (s, 1H), 9.06 (d, J=1.1 Hz, 1H), 8.94 (d, J=1.0 Hz, 1H), 8.63 (d, J=5.3 Hz, 1H), 7.54 (d, J=5.3 Hz, 1H), 3.93 (s, 3H).

Workup

filtrationThe resulting grey slurry was filtered whilst hot through a pad of celite
washthe pad washed with hot THF and 25% methanol in dichloromethane
concentrationThe combined filtrate was concentrated in-vacuo
customthe resultant residue triturated with methanol (10 mL)
filtrationThe resultant solid was collected by filtration
waitleft to air
customdry

Sources & evidence

ORD record: ord-ad7969c9339a4e38bd36216aa11d49c9
Source dataset: uspto-grants-2016_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09440976B2

Reaction notes

Loading…