Showing posts with label 7-dichloronorcarane. Show all posts
Showing posts with label 7-dichloronorcarane. Show all posts

Sunday 31 August 2014

7,7-dichlorobicyclo[4.1.0]heptane (7,7-dichloronorcarane

7,7-dichlorobicyclo[4.1.0]heptane (7,7-dichloronorcarane

Cyclohexene+Chloroform
NaOH,Pr3N
reacts to
7,7-Dichlorobicyclo[4.1.0]heptane+Hydrogen chloride; Side reactions


Synthesis of 7,7-dichlorobicyclo[4.1.0]heptane (7,7-dichloronorcarane) from cyclohexene

Reaction type:addition to alkenes, elimination, cycloaddition
Substance classes:alkene, carbene, chloroalkane
Techniques:stirring with magnetic stir bar, adding dropwise with an addition funnel, distilling under reduced pressure, evaporating with rotary evaporator, shaking out, extracting, filtering, use of an ice cooling bath, heating with oil bath
http://kriemhild.uft.uni-bremen.de/nop/en/instructions/pdf/3005_en.pdf

Instruction (batch scale 100 mmol)
Equipment
100 mL three neck round bottom flask, reflux condenser, addition funnel with pressure
balance, heatable magnetic stirrer, magnetic stir bar, thermometer for inside of the flask,
separating funnel, destillation apparatus, rotary evaporator, oil bath, ice bath, vacuum pump
Substances
cyclohexene (bp 83 °C) 8.21 g (10.1 mL, 100 mmol)
chloroform (bp 61 °C) 48.0 g (32.7 mL, 400 mmol)
sodium hydroxide 16.0 g (400 mmol)
tri-n-propylamine (bp 156 °C) 0.14 g (0.19 mL, 1.0 mmol)
water 16 mL
ethanol (bp 78 °C) 1 mL
n-pentane (bp 36 °C) 120 mL
sodium sulfate for drying about 5 g
sodium chloride about 18 g
Reaction
Into a 100 mL three neck round bottom flask equipped with a reflux condenser addition
funnel, thermometer for measuring the inside temperature and magnetic stir bar, 8.21 g
(10.1 mL, 100 mmol) cyclohexene 0.14 g (0.19 mL, 1.0 mmol) tri-n-propylamine, 48.0 g
(32.7 mL, 400 mmol) chloroform and 1 mL ethanol is added. The mixture is cooled to 0 °C
with an ice bath, then under stirring and further cooling in the ice bath a solution of 16.0 g
(400 mmol) sodium hydroxide in 16 mL water is added through an addition funnel. The
mixture should be stirred vigourously during the next 20 minutes at 0 °C. After this time the
mixture is further stirred during 1 hour at room temperature and 3 hours at 50 °C.
Work up
Chloroform is evaporated with a rotary evaporator, then the residue is transferred with about
50 mL water and 30 mL n-pentane into a separating funnel. The organic phase is separated,
the aqueous phase is further extracted three times with 30 mL pentane. If an emulsion is
formed the aqueous phase is saturated with NaCl. The combined organic phases are dried over
sodium sulfate. The solution is filtered from sodium sulfate and the solvent is evaporated with
a rotary evaporator, yielding a nearly colourless liquid as crude product. The crude yield is
14.6 g. The crude product is distilled under reduced pressure.
Yield: 13.6 g (82.3 mmol, 82%), colourless liquid; bp 77 °C (11 hPa)

Operating scheme

Operating schemeOperating scheme

Equipment

Batch scale:0.01 mol0.1 mol1 molCyclohexene

two-necked flask 10 mLtwo-necked flask 10 mLreflux condenserreflux condenser
heatable magnetic stirrer with magnetic stir barheatable magnetic stirrer with magnetic stir barthermometerthermometer
graduated pipettegraduated pipetteseparating funnelseparating funnel
microdistillation apparatusmicrodistillation apparatusrotary evaporatorrotary evaporator
oil bathoil bathice bathice bath
vacuum pumpvacuum pump

................ 


pure product chromatogram

GC: pure productcolumnSE-54, L= 25 m, ID 0.32 mm, DF 0.25 µm (Macherey & Nagel)inletGerstel KAS, injector: 250°C, split injection 1:20, 0.15 µLcarrier gasN2, pre-column pressure 62 kPa, 1.04 mL/minoven80 °C (1 min), 10 °C/min --> 250 °C (30 min)detectorFID, 275 °Cintegrationpercent concentration calculated from relative peak area

1H NMR


1H-NMR: 7,7-Dichlorobicyclo[4.1.0]heptane
500 MHz, CDCl3
delta [ppm]mult.atomsassignment
1.12-1.36m4 HC4-H, C5-H
1.61-1.71m4 HC3-H, C6-H
1.88-1.98m2 HC1-H, C2-H
7.26s1 HCHCl3


13C NMR


3C-NMR: 7,7-Dichlorobicyclo[4.1.0]heptane
125 MHz, CDCl3
delta [ppm]assignment
18.9C4, C5
20.2C3, C6
25.8C2, C1
67.4C7
76.5-77.5CDCl3

IR
IR: 7,7-Dichlorobicyclo[4.1.0]heptane
[Film, T%, cm-1]
[cm-1]assignment
2944, 2855aliph. C-H valence
796C-Cl valence