Exp071.JPG

Objective

To synthesize N-(1-Cyclohexenyl)formamide from Cylohexanone and formamide, following the protocol described by Maison, Schlemminger, et.al.

Procedure

This is a repeat of Exp 071 with minor changes to the procedure.
Cylohexanone (9.3 ml, 0.1 mol) was dissolved in toluene (50 ml) in a 500 ml round bottom flask. To this solution fomamide (5.61 ml, 0.11 mol) and conc.H2SO4 (0.5 ml) was added. The round bottom flask was connected to a dean-stark apparatus under reflux conditions on a heating mantle for 24h. The solution was washed with water (10 mL) and brine (10 mL) and again with water (10ml).The organic layer obtained after separation was dried with anhydrous MgSO4 (2 g) and set up a rotovap maintained at 45C, connected to a high vac.

Results

NMR of Reactants
Cyclohexanone HNMR [in CDCl3]
Cyclohexanone CNMR [in CDCl3]
Fomamide HNMR [neat]
Formamide HNMR [in CD3OD]
Formamide CNMR [in CD3OD]

Discussion

  1. The procedure has not been followed complety, the reactants were scaled 20 time down, however the catalyst was only scaled down to half the original protocol calls for. Also the original protocol calls for refluxing the reaction mixture for 12 h only, however the reaction mixture was refluxed for 24 h. This experiment may not bear similar results to one reported in the published data mainly referenced.

Conclusion

The experiment was unsuccessful..because the procedure (main protocol) was not followed entirely.

Log

2007-03-20

20:10 : Added cylcohexanone (9.3 ml) to a clean 500ml round bottom flask. Toluene (500 ml) was added to it.
20:15 : Added formamide (5.61 ml) to the r.b. flask.
20:17 : Added conc. H2SO4 (0.5 ml) to the r.b. flask
20:20 : Started heating the r.b.flask connected to a dean-stark apparatus on a heating mantle.

2007-03-21

07:45 : Only about 1mL of water settled down in the arm of the dean-stark apparatus, therefore the variac dial was turned up by five units (70 to 75) so as to invigorate the reflux.
08:00: The reaction started to reflux vigorously.
20:20 : Turned heating mantle off. The solution had turned deep green, and 5.1 mL of water had accumulated in the dean-stark apparatus.
20:35 : The pH of reaction mixture was very slightly acidic between 5-6)
20:45: Added distilled water (10 mL) transferred to a separatory funnel, separated the bottom aqueous layer, added brine solution (10 mL) to the sep. funnel, separated the layers, washed the organic layer once again with distilled water (10 mL), separated the layers again.
21:00 : Transferred the organic layer to a rb flask, added MgSO4 (2 g), filtered through a buchner funnel and set the obtained green organic solution on a rotovap connected to a high vac, with the water bath set to 45 C.
21:10 : The aqueous layers which were gathered to gether turned cloudy (yellow) upon the addition of brine extract from the sep. funnel.

2007-03-22

10:30 : Removed the organic layer from the vac (rotovap) and obtained 74A (5.7 g).

Tags

Cyclohexanone :InChI=1/C6H10O/c7-6-4-2-1-3-5-6/h1-5H2
Formamide: InChI=1/CH2O/c1-2/h1H2
N-Cylohexenylformamide: InChI=1/C7H11NO/c9-6-8-7-4-2-1-3-5-7/h4,6H,1-3,5H2,(H,8,9)