Potassium Carbonate → ethyl 6-nitro-2-(trifluoromethyl)-2H-1-benzopyran-3-carboxylate

HRID 722292

Reaction equation

[N+:1]([C:4]1[CH:11]=[C:8]([CH:9]=O)[C:7]([OH:12])=[CH:6][CH:5]=1)([O-:3])=[O:2].[F:13][C:14]([F:23])([F:22])/[CH:15]=[CH:16]/[C:17]([O:19][CH2:20][CH3:21])=[O:18].C([O-])([O-])=O.[K+].[K+]>CN(C=O)C.O.C(OCC)C>[N+:1]([C:4]1[CH:5]=[CH:6][C:7]2[O:12][CH:15]([C:14]([F:13])([F:23])[F:22])[C:16]([C:17]([O:19][CH2:20][CH3:21])=[O:18])=[CH:9][C:8]=2[CH:11]=1)([O-:3])=[O:2]

Participants

Conditions

Temperature: 60 °C

Procedure

A mixture of 5-nitrosalicylaldehyde (4.80 g, 28.7 mmol) and ethyl 4,4,4-trifluorocrotonate (6.6 g, 39.4 mol) in anhydrous DMF was warmed to 60° C. and treated with anhydrous K2CO3 (3.90 g, 28.9 mol). The solution was maintained at 60° C. for 20 hours, cooled to room temperature, diluted with water, and extracted with ethyl acetate. The organic extracts were washed with brine, dried over anhydrous MgSO4, filtered and concentrated in vacua to afford an oil. The oil was dissolved in diethyl ether (5 mL). Hexanes was added until the solution became cloudy. Upon standing at room temperature overnight the ester was obtained as yellow crystals (0.856 g, 7% yield). This material was of sufficient purity to be used in subsequent steps without further purification. 1H NMR (CDCl3/300 MHz) 8.15–8.19 (m, 2H), 7.74 (s, 1H), 7.09 (d, 1H, J=8.9 Hz), 5.81 (q, 1H, J=5.8 Hz), 4.29–4.39 (m, 2H), 1.35 (t, 3H, J=6.0 Hz),

Workup

temperatureThe solution was maintained at 60° C. for 20 hours
temperaturecooled to room temperature
extractionextracted with ethyl acetate
washThe organic extracts were washed with brine
dry with materialdried over anhydrous MgSO4
filtrationfiltered
concentrationconcentrated in vacua
customto afford an oil

Sources & evidence

ORD record: ord-684e61751e574bbc8516c34e94ddaa94
Source dataset: uspto-grants-2006_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07138411B2

Linked notes

Loading…