ChemicalBook CAS DataBase List 1,2,3,4,5-Pentamethylcyclopentadiene

1,2,3,4,5-Pentamethylcyclopentadiene synthesis

12synthesis methods

Product Name:1,2,3,4,5-Pentamethylcyclopentadiene
CAS Number:4045-44-7
Molecular formula:C10H16
Molecular Weight:136.23

54458-61-6 Synthesis

54458-61-6
208 suppliers
$6.00/1g

676-58-4 Synthesis

676-58-4
282 suppliers
$15.00/25ml

4045-44-7
233 suppliers
$11.00/1g

Yield:-

Reaction Conditions:

Stage #1: 2,3,4,5-tetramethyl-2-cyclopenten-1-one;methylmagnesium chloride in tetrahydrofuran at 0 - 20; for 3 h;
Stage #2: with acetic acid in tetrahydrofuran;
Stage #3: with hydrogenchloride;water in diethyl ether; for 0.5 h;

Steps:

1.A

Cyclop entadienes were synthesized starting from substituted cyclopentenones prepared according to procedure previously described in patent WO 2006051503.Cyclopentadienes were generally obtained in high molar yields (>80%) and purity (> 95%).Rⁿ is an alkyl or alkenyl groupA solution of cyclopentenone (1 equivalents) in THF (1.6 M) was added at 0⁰C under inert atmosphere to a solution of R¹¹MgCl (1.2 equivalents). Reaction mixture was then allowed to warm to room temperature and stirred for 3 hours. Acetic acid 10% was then added to the reaction mixture and the organic phase was extracted with Et₂O. HCl (20% in water) was added to the organic phase and allowed to stir for 30 minutes. The organic phase was then neutralized with NaHCO₃ (5% in water). Washing with water, drying and evaporation of solvent gave a crude product, which was purified by distillation.

References:

WO2008/120175,2008,A1 Location in patent:Page/Page column 13