C([Li])CCC.Br.[CH2:7]([NH:9][C:10]1[C:15]([CH3:16])=[CH:14][CH:13]=[CH:12][C:11]=1[CH3:17])[CH3:8].[CH2:18]([N:20]([C:29]#[N:30])[C:21]1[C:26]([CH3:27])=[CH:25][CH:24]=[CH:23][C:22]=1[CH3:28])[CH3:19].C1COCC1>CCCCCC>[CH3:17][C:11]1[CH:12]=[CH:13][CH:14]=[C:15]([CH3:16])[C:10]=1[N:9]([CH2:7][CH3:8])[C:29]([N:20]([C:21]1[C:26]([CH3:27])=[CH:25][CH:24]=[CH:23][C:22]=1[CH3:28])[CH2:18][CH3:19])=[NH:30]n-Butyllithium (20.5 mL, 1.6 M in hexane, 32.8 mmol) was added dropwise to a stirred suspension of N-ethyl-2,6-dimethylaniline hydrobromide (3.8 g, 16.5 mmol) in hexane (40 mL) at 0° C. The reaction mixture was stirred for 1 h at room temperature and cooled subsequently to −80° C. N-Ethyl-N-cyano-2,6-dimethylaniline (2.92 g, 16.8 mmol) was added drop wise at −80° C. after which the reaction mixture was allowed to slowly warm up to room temperature. The resulting reaction mixture was stirred for 2 h at room temperature, during which hexane (60 mL) and THF (20 mL) were added to form a homogeneous solution. The reaction mixture was quenched and washed with water (100 mL). The organic layer was separated, the aqueous layer was extracted with diethyl ether (100 mL) and the combined organic layers were dried with Na2SO4. Filtration and rotatory evaporation of the volatiles yielded the desired guanidine as a yellow waxy material. Yield: 5.3 g (99%).
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