4-Pyridinecarboxaldehyde → (Z)-4-[2-(3-Cyclopentyloxy-4-methoxyphenyl)ethenyl]pyridine

HRID 922

Reaction equation

HRID 922 reaction equation
[O-]CC.[Na+].[N:5]1[CH:10]=[CH:9][C:8]([CH:11]=O)=[CH:7][CH:6]=1.[Cl-].[CH:14]1([O:19][C:20]2[CH:21]=[C:22]([C:28]3C=CC=CC=3[P+](C)(C3C=CC=CC=3)C3C=CC=CC=3)[CH:23]=[CH:24][C:25]=2[O:26][CH3:27])[CH2:18][CH2:17][CH2:16][CH2:15]1>C(O)C>[CH:14]1([O:19][C:20]2[CH:21]=[C:22](/[CH:28]=[CH:11]\[C:8]3[CH:7]=[CH:6][N:5]=[CH:10][CH:9]=3)[CH:23]=[CH:24][C:25]=2[O:26][CH3:27])[CH2:15][CH2:16][CH2:17][CH2:18]1

Participants

5

Reactant 3

HCID 133894-PyridinecarboxaldehydeHCID 2723922Sodium ethoxideHCID 86750869(3-Cyclopentyloxy-4-methoxyphenyl)-methyltriphenylphosphonium chloride

Product 1

HCID 67015247(Z)-4-[2-(3-Cyclopentyloxy-4-methoxyphenyl)ethenyl]pyridineYield 11.9%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent2×

Procedure

A solution of sodium ethoxide [prepared from sodium (0.10 g, 4.50 mmol)] in ethanol (50 ml) was added over 5 min to a stirred mixture of 4-pyridine carboxaldehyde (0.44 g, 4.10 mmol) and (3-cyclopentyloxy-4-methoxyphenyl)-methyltriphenylphosphonium chloride (2.00 g, 4.08 g) in ethanol (30 ml). After 2h, the reaction mixture was concentrated in vacuo and the residue partitioned between EtOAc (75 ml) and brine (50 ml). The organic layer was separated, then dried (MgSO4) and concentrated in vacuo. A 1H n.m.r. spectrum indicated that the mixture consisted of a 3:2 mixture of (Z): (E)title compound (and triphenylphosphine oxide). A portion (0.6 g) of the mixture was subjected to chromatography (SiO2 ; hexane to EtOAc) to afford pure/Z-title compound (0.14 g) as a pale yellow solid m.p. (Found: C, 77.18; H, 7.16; N, 4.63. C19H21NO2 requires C, 77.26; H, 7.17; N, 4.74%); δH (300 MHz; CDCl3) 1.5-1.55 (2H, br m, cyclopentyl H's), 1.65-1.9 (6H, br m, cyclopentyl H's), 3.83 (3H, s, OMe), 4.44 (1H, br m, OCHCH2), 6.40 (1H, d, J 12.2 Hz, CH=CH), 6.65-6.80 (4H, m, ArH ortho to OMe+2×ArH meta to OMe+CH=CH), 7.15 (2H, ca. d, J 6.0 Hz, pyridine H2, H6); m/z 295 (M+, 22%), 228 (15), 227 (100), 226 (94), 198 (35), 184 (15), 166 (12), 43 (19), and 41 (29).

Workup

  1. concentrationAfter 2h, the reaction mixture was concentrated in vacuo
  2. customthe residue partitioned between EtOAc (75 ml) and brine (50 ml)
  3. customThe organic layer was separated
  4. dry with materialdried (MgSO4)
  5. concentrationconcentrated in vacuo
  6. additionconsisted of a 3:2 mixture of (Z)

Sources & evidence

ORD record
ord-71da5db547d042afaa9286f9adab88a0
Source dataset
uspto-grants-1998_03
Patent number
US05723460

Linked notes

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