4-Cyanophenylhydrazine Hydrochloride → 2-(4-Cyanophenyl)-3-cyclopentyl-2,3,3a,4-tetrahydrochromeno[4,3-c]pyrazole-7-carboxylic acid
Reaction equation
[CH:1]1([CH:6]=[C:7]2[C:16](=O)[C:15]3[C:10](=[CH:11][C:12]([C:18]([O:20]C)=[O:19])=[CH:13][CH:14]=3)[O:9][CH2:8]2)[CH2:5][CH2:4][CH2:3][CH2:2]1.Cl.[NH:23]([C:25]1[CH:32]=[CH:31][C:28]([C:29]#[N:30])=[CH:27][CH:26]=1)[NH2:24]>>[C:29]([C:28]1[CH:31]=[CH:32][C:25]([N:23]2[CH:6]([CH:1]3[CH2:2][CH2:3][CH2:4][CH2:5]3)[CH:7]3[CH2:8][O:9][C:10]4[CH:11]=[C:12]([C:18]([OH:20])=[O:19])[CH:13]=[CH:14][C:15]=4[C:16]3=[N:24]2)=[CH:26][CH:27]=1)#[N:30]Participants
Procedure
The title compound was prepared from methyl 3-(cyclopentylmethylene)-4-oxochroman-7-carboxylate; Preparation 31 (286 mg, 1.0 mmol) and 4-hydrazinylbenzonitrile hydrochloride (Aldrich; 254 mg, 1.5 mmol) according to Method B and Method C. 2-(4-Cyanophenyl)-3-cyclopentyl-2,3,3a,4-tetrahydrochromeno[4,3-c]pyrazole-7-carboxylic acid was obtained (yellow solid, 142 mg, 0.367 mmol, 37% yield). The title compound was largely present as (±)-(3RS,3aSR)-2-(4-cyanophenyl)-3-cyclopentyl-2,3,3a,4-tetrahydrochromeno[4,3-c]pyrazole-7-carboxylic acid. 1H NMR (400 MHz, DMSO-d6) δ ppm 13.16 (br. s., 1H), 7.93 (d, J=7.8 Hz, 1H), 7.53-7.66 (m, 3H), 7.46 (s, 1H), 7.27 (d, J=9.0 Hz, 2H), 4.90 (dd, J=9.4, 7.0 Hz, 1H), 4.77 (dd, J=10.4, 5.7 Hz, 1H), 4.30 (dd, J=12.7, 10.7 Hz, 1H), 3.98 (ddd, J=12.9, 9.8, 5.9 Hz, 1H), 2.02-2.16 (m, 1H), 1.56-1.67 (m, 1H), 1.43-1.55 (m, 3H), 1.29-1.43 (m, 2H), 1.13-1.29 (m, 2H). ES-MS m/z 388 (M+H).
Sources & evidence
- ORD record
- ord-f355e70f23ef49c398a47b2f64bdac44
- Source dataset
- uspto-grants-2010_08
- Patent number
- US07781428B2
Reaction notes
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