Styrene → HCID 57626265, compound

HRID 2077266Notes

Reaction equation

[CH2:1]([O:3][C:4](=[O:13])[CH:5]=[N:6][NH:7][CH2:8][CH2:9][CH2:10][CH2:11][CH3:12])[CH3:2].ClN1C(=O)CCC1=O.[CH2:22]=[CH:23][C:24]1[CH:29]=[CH:28][CH:27]=[CH:26][CH:25]=1.C(=O)(O)[O-].[K+]>C(OC(=O)C)C.O>[CH2:8]([N:7]1[CH:23]([C:24]2[CH:29]=[CH:28][CH:27]=[CH:26][CH:25]=2)[CH2:22][C:5]([C:4]([O:3][CH2:1][CH3:2])=[O:13])=[N:6]1)[CH2:9][CH2:10][CH2:11][CH3:12]

Participants

Conditions

Temperature: 60 °C

Procedure

To a magnetically stirred solution of (pentylhydrazono)acetic acid ethyl ester (Intermediate II-1) (35.16 g, 179 mmol) in ethylacetate (450 ml) was added N-chlorosuccinimide (NCS) (26.34 g, 197 mmol) and the resulting mixture was heated at 60° C. for 1 hour in a nitrogen atmosphere. To the reaction mixture was added styrene (41.1 ml, 359 mmol) and potassium bicarbonate (89.8 g, 897 mmol) and water (8 ml). The resulting mixture was heated at 70° C. for 16 hours. The resulting mixture was allowed to attain room temperature, concentrated in vacuo and the resulting residue was chromatographically separated using Sepacore equipment (eluant: dichloromethane/methanol=98/2 v/v) to give ethyl 1-(n-pentyl)-5-phenyl-4,5-dihydro-(1H)-pyrazole-3-carboxylate (Intermediate (V-1) (12.1 g, 22% yield) as an oil. 1H-NMR (400 MHz, CDCl3) δ 0.83 (t, J=7, 3H), 1.13-1.28 (m, 4H), 1.35 (t, J=7, 3H), 1.53-1.67 (m, 2H), 2.89 (dd, J=16 and 13, 1H), 3.01-3.09 (m, 1H), 3.14-3.22 (m, 1H), 3.41 (dd, J=16 and 12, 1H), 4.31 (double (diastereotopic) quartet, J˜7, 2H), 4.63 (dd, J=13 and 12, 1H), 7.27-7.39 (m, 5H).

Workup

temperatureThe resulting mixture was heated at 70° C. for 16 hours
customto attain room temperature
concentrationconcentrated in vacuo
customthe resulting residue was chromatographically separated

Sources & evidence

ORD record: ord-da0d3bf656334772a62840f386f89b5d
Source dataset: uspto-grants-2011_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07928134B2

Reaction notes

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