4,4′-Methylenebis(2,6-dimethylaniline)

Off-white powder

To a solution of 2, 6-dimethylaniline (10.00 g, 0.083 mol) and formaldehyde (4.03 g, 0.054 mol, 0.65 eq. ) was added dilute hydrochloric acid (2.2 ml, 0.1 M). The biphasic solution was stirred at 70 °C overnight. The dark reddish solution was left to cool to ambient temperature and diluted with dichloromethane (15 ml). The minimum amount of concentrated hydrochloric acid (2 ml) was introduced and the solution stirred at room temperature for 2 hours before being filtered. The white salt collected was washed thoroughly with dichloromethane and air-dried. The salt was suspended in diethyl ether (70 ml) and stirred with an aqueous solution of saturated sodium hydroxide until the dissolution of the solid. The aqueous phase was extracted with diethyl ether (2 x 70 ml) and the combined organic phases dried over magnesium sulfate, filtered and concentrated under reduced pressure to give 2a as an orange solid (8.97 g, 86percent).To a suspension of 2a (0.50 g, 1.97 mmol) in absolute ethanol (2 ml) was added 2- pyridinecarboxaldehyde (0.56 ml, 5.91 mmol, 3 eq. ) and one drop of formic acid. The mixture was stirred at 45 °C overnight. On cooling to room temperature the suspension was filtered, washed with cold ethanol and dried under reduced pressure to afford 17 as a yellow solid (0.28 g, 18percent). Compound 17: ES mass spectrum, m/z 433 [M+H]+; 1H NMR (CDCl3), delta 2.12 (s, 12H, CH3), 3.77 (s, 2H, CH2), 6.88 (s, 4H, Ar-H), 7.2-7.4 (m, 2H, Py-H), 7.7-7.8 (m, 2H, Py- H), 8.1-8.3 (m, 4H, Py-H, HC=N), 8.6-8.7 (m, 2H, Py-H) ; 13C NMR (CDCl3, 1H gated decoupled), delta 18.4 (s, CH3), 40.9 (s, CH2), 121.2 (s, Ar), 125.2 (s, Ar), 127.0 (s, Ar), 128.7 (s, Ar), 136.7 (s, Ar), 137.1 (s, Ar), 148.3 (s, Ar), 149.6 (s, Ar), 154.6 (s, Ar), 163.4 (s, C=N). In addition, a single crystal X-ray diffraction study of 17 has confirmed the structural type.EXAMPLE VI A suitable reaction vessel containing 0.55 mol of 40percent aqueous dimethylamine, 1.17 mols of acetic acid, 100 ml of methanol, and 0.55 mol of 37percent aqueous formaldehyde was allowed to warm to room temperature while adding 0.5 mol of 2, 6-dimethylaniline. The reaction mixture was then heated, maintained at 67-81° C. for about three hours, cooled, and worked up to provide a crude product which was determined by GC analysis to contain 2, 2', 6, 6'tetramethyl-4, 4'-methylenebisaniline and 2, 6-dimethyl-4-dimethylaminomethylaniline in an area percent ratio of 1.7/1.0, as well as a small amount of 2, 6-dimethyl-4-methoxymethylaniline.In a reaction vessel was placed 2 gms (0.01 mole) of 2, 6-dimethylaniline hydrochloride and 30 gms of diethyl carbonate. The stirred mixture was heated to 124° C. at which time 15 ml dimethylsulfoxide was added. The suspension turned to a clear purple solution following which a crystalline precipitate formed. The diethyl carbonate was distilled out under vacuum at 80° C. and then aqueous caustic was added in an amount which made the mixture alkaline. The mixture was then extracted with 40 ml of toluene. The toluene extract was water washed and then the toluene was distilled out leaving a residue. This residue was distilled using a Kugel-rohr distillation set-up. The fraction removed at about 170° C. was crystallized from isporopanol yielding 4, 4'-methylenebis-(2, 6-dimethylaniline), mp 119-120° C.To a solution of 2, 6-dimethylaniline (10.00 g, 0.083 mol) and formaldehyde (4.03 g, 0.054 mol, 0.65 eq. ) was added dilute hydrochloric acid (2.2 ml, 0.1 M). The biphasic solution was stirred at 70 °C overnight. The dark reddish solution was left to cool to ambient temperature and diluted with dichloromethane (15 ml). The minimum amount of concentrated hydrochloric acid (2 ml) was introduced and the solution stirred at room temperature for 2 hours before being filtered. The white salt collected was washed thoroughly with dichloromethane and air-dried. The salt was suspended in diethyl ether (70 ml) and stirred with an aqueous solution of saturated sodium hydroxide until the dissolution of the solid. The aqueous phase was extracted with diethyl ether (2 x 70 ml) and the combined organic phases dried over magnesium sulfate, filtered and concentrated under reduced pressure to give 2a as an orange solid (8.97 g, 86percent).

Molecular Weight:254.37
XLogP3:3.9
Hydrogen Bond Donor Count:2
Hydrogen Bond Acceptor Count:2
Rotatable Bond Count:2
Exact Mass:254.178298710
Monoisotopic Mass:254.178298710
Topological Polar Surface Area:52
Heavy Atom Count:19
Complexity:239
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes