tert-Butyl (triphenylphosphoranylidene) acetate → 4-(7-methyl-1H-indazol-5-yl)-but-2-enoic Acid Tert-Butyl Ester

HRID 2099736

Reaction equation

HRID 2099736 reaction equation
[CH3:1][C:2]1[CH:3]=[C:4]([CH2:11][CH:12]=O)[CH:5]=[C:6]2[C:10]=1[NH:9][N:8]=[CH:7]2.[C:14]([O:18][C:19]([CH:21]=P(C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)=[O:20])([CH3:17])([CH3:16])[CH3:15]>O1CCCC1>[C:14]([O:18][C:19](=[O:20])[CH:21]=[CH:12][CH2:11][C:4]1[CH:5]=[C:6]2[C:10](=[C:2]([CH3:1])[CH:3]=1)[NH:9][N:8]=[CH:7]2)([CH3:17])([CH3:16])[CH3:15]

Participants

4

Procedure

Tetrahydrofuran (8 mL) was added to a flask containing (7-methyl-1H-indazol-5-yl)-acetaldehyde (1.94 mmol, 1.0 equiv) and (tert-butoxycarbonyl-methylene)triphenylphosphorane (1.46 g, 3.88 mmol, 2.0 equiv) at room temperature under nitrogen. The resulting yellow solution was stirred overnight (15 h). LCMS indicated completion. The mixture was partitioned between water and ethyl acetate. The organic layer was separated and washed with brine, dried over sodium sulfate and concentrated in vacuo. The residue was purified by flash column chromatography to afford the desired product as a yellow oil (272 mg, 51.5% for two steps). MS (ESI) [M+H]+=273; 1H NMR (400 MHz, CDCl3) δ 12.3 (br., 1H), 8.06 (s, 1H), 7.36 (s, 1H), 7.04 (m, 1H), 6.96 (s, 1H), 5.74 (dd, J=15.6 and 1.6 Hz, 1H), 3.54 (d, J=6.8 Hz; 2H), 2.57 (s, 3H), 1.47 (s, 9H).

Workup

  1. customThe mixture was partitioned between water and ethyl acetate
  2. customThe organic layer was separated
  3. washwashed with brine
  4. dry with materialdried over sodium sulfate
  5. concentrationconcentrated in vacuo
  6. customThe residue was purified by flash column chromatography

Sources & evidence

ORD record
ord-fb52fe7e55494e9d93e057ec2d088ad2
Source dataset
uspto-grants-2009_08
Patent number
US07569578B2

Linked notes

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