Methyl-(p-trans-heptylcyclohexyl)carbamate, prepared in high yield from the amide by Hoffman degradation in methanol/bromine, see secondary reference 1.

Potassium hydroxide, pellets, Sigma Aldrich, 85+%, 22,147-3.

Ethyl alcohol, reagent, denatured, anhydrous,Sigma Aldrich, 27,764-9.

To a 100ml round bottom three neck flask, equipped with heating mantle, mechanical stirrer, water condenser and  nitrogen inlet was charged 32ml of 200 proof ethanol, 8 ml of deionized water and 0.512g (1.55 mmol) of  methyl- (p-trans-heptylcyclohexyl)carbamate. The mixture was stirred until homogeneous. 10g of potassium hydroxide pellets were then added and the mixture stirred until all of the pellets has dissolved. The solution was refluxed under nitrogen for 24 hours and then allowed to cool to room temperature. The reaction mixture was transferred to a 100ml round bottom flask and the ethanol removed on a rotory evaporator (water bath, bath temperature ~ 60⁰, water aspirator pressure). The aqueous residue was cooled to room temperature, transferred to a 100 ml separatory funnel, and extracted three times with 10ml ether portions. The combined ether extracts were dried for 2 hours over 2g anhydrous sodium sulfate and  the ether solution decanted off to a 100 ml round bottom flask. The sodium sulfate residue was shaken with 10 additional ml of ether which was decanted and  combined with the earlier extracts. The ether was removed on  a rotory evaporator (water bath, bath temperature ~ 60⁰), yielding 0.348g (88%) of essentially pure amine, which solidified on standing at room temperature. The material may be further purified by distillation on a short path Kugelrohr apparatus (0.1mm, pressure, oil bath temperature ~140⁰ ) to yield an analytically pure sample.

CAUTION! Potassium hydroxide pellets are irritating and hygroscopic. Weigh quickly in a glove box if possible. Wear latex gloves.

The aqueous potassium hydroxide/ethanol medium allows solubility of both base and organic carbamate, facilitating hydrolysis.

By entirely analogous reactions other amines were synthesized in high yield by this procedure. See primary and secondary references.

B.p. ~ 140⁰ (0.1 mm), m.p. 55.8⁰

Ir (neat film)  3420, 3350, 3250, (N-H stretches), 3050, (aromatic C-H stretch), 2950, (aliphatic C-H stretch),1630, (aromatic C-C stretch), cm-1.

Analysis: Calculated for C₁₉H₃₁N: C 83.45, H 11.43, N 5.12; Found: C 83.76, H 11.18, N5.09

John H. MacMillan and Mortimer M. Labes, "Low Transition Temperature Liquid Crystalline Amines Incorporating the Trans-1,4-Cyclohexane Ring System", Molecular Crystals and Liquid Crystals, Vol. 55, p 61, (1979).

John H. MacMillan and Mortimer M. Labes, "Low Transition Temperature Liquid Crystalline Amines Incorporating the Biphenyl Ring System", Mol. Crystals and Liquid Crystals Letters, Vol. 56, p51, (1979).

DOI: Link: http://dx.doi.org/10.1080/01406567908071966

John H. MacMillan and Mortimer M. Labes, "Amine Substituted Liquid Crystal Compositions", U.S. Patent 4,293,193, Oct. 6, 1981.

Chemspider deposition:  http://www.chemspider.com/Chemical-Structure.29354034.html