Water → 1,3-Cyclopentadiene, 1-pentyl

Temperature

-55 °C

To a solution of sodium cyclopentadienide (71 mmole, 1.89 M in THF) in 20 ml of THF was added 10 ml of hexamethylphosphoramide. The solution was cooled to -55° C. and 1-bromopentane (10.5 g. 70 mmole) was added dropwise with stirring over a period of 30 min. After the addition was completed, the reaction mixture was stirred at -30°-40° C. for 30 minutes and at autogeneous temperature for 30 minutes, then poured into cold water and extracted with pentane, (3×80 ml). The pentane extracts were combined, washed with water (3×100 ml) dried over anhydrous sodium sulfate, filtered and concentrated in a rotary evaporator (water bath temperature 20° C.). The residue was distilled to give 8.1 g (85%) of pentylcyclopentadiene, b.p. 52°/8 mm Hg.

1. additionAfter the addition
2. stirringthe reaction mixture was stirred at -30°-40° C. for 30 minutes and at autogeneous temperature for 30 minutes
3. extractionextracted with pentane, (3×80 ml)
4. washwashed with water (3×100 ml)
5. dry with materialdried over anhydrous sodium sulfate
6. filtrationfiltered
7. concentrationconcentrated in a rotary evaporator (water bath temperature 20° C.)
8. distillationThe residue was distilled

ORD record

ord-7bbd278092ab474baa023721fdf716a2

Source dataset

uspto-grants-1982_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04329508