Short-RInChIKey=SA-FUHFF-UHFFFADPSC-ARVDXDODRG-UHFFFADPSC-NUHFF-NXYUF-NUHFF-ZZZ

To an ice-cold and stirred solution of ethyl cis-2-amino-1-cyclohexanecarboxylate hydrochloride (3.00 g, 14.40 mmol, 1.0 eq.) and Et3N (4.20 ml, 30.30 mmol, 2.1 eq) in MeCN (67.5 ml) a solution of N,N,N',N'‑tetramethylchloroformamidinium chloride (2.71 g, 15.84 mmol, 1.1 eq) in MeCN (67.5 ml) was added dropwise. The reaction mixture was heated to 110 °C and was refluxed for 3 h. At room temperature NaOH solution (1.2 g, 30.00 mmol, 2.1 eq) in water (12.0 ml) was added and stirred for 90 s. MeCN and Et3N were removed in vacuo, KOH (50 wt%, 9.0 ml) was added to the reaction mixture and the aqueous phase was extracted with MeCN (3 x 30 ml). The combined organic layers were dried with MgSO4 and filtered over Celite®. The solvent was removed in vacuo affording ethyl-2-((bis(dimethylamino)methylen)amino)cyclohexan-1-carboxylate as a colourless oil (77%, 11.1 mmol, 3.0 g).