Tris(dimethylamino)methane (TDAM) is the simplest representative of the tris(dialkylamino)methanes of the general formula (R<sub>2</sub>N)<sub>3</sub>CH in which three of the four of methane's hydrogen atoms are replaced by dimethylamino groups (âÂÂN(CH<sub>3</sub>)<sub>2</sub>). Tris(dimethylamino)methane can be regarded as both an amine and an orthoamide.
Tris(dimethylamino)methane is a strong base and can be used as a formylation agent, as aminomethylenation reagent and as a source for the basic bis(dimethylamino)carbene of the formula (R<sub>2</sub>N)<sub>2</sub>C:.
Tris(dimethylamino)methane is formed in the reaction of N,N,Nâ²,Nâ²-Tetramethylformamidinium chloride (TMF-Cl) or bis(dimethylamino)acetonitrile with lithium dimethylamide or sodium dimethylamide with yields between 55 and 84%.
From dimethylamine and trimethoxyborane sodium dimethylamide is formed in situ in the presence of sodium hydride which reacts with N,N,N,N-tetramethylformamidinium chloride in 84% yield to tris(dimethylamino)methane and with bis(dimethylamino)acetonitrile in 77% yield.
The reaction of the dimethylformamide (DMF) dimethylacetal, HC(OCH<sub>3</sub>)<sub>2</sub>N(CH<sub>3</sub>)<sub>2</sub>, (from the DMFâÂÂdimethyl sulfatecomplex and sodium methoxide) with dimethylamine in the presence of the acidic catalyst 2,4,6-tri-tert-butylphenol (which is largely stable to the alkylating agent) produces tris(dimethylamino)methane.
Tris(dimethylamino)methane is formed in good yield (83%) in the reaction of DMF with tetrakis(dimethylamino)titanium(IV).
N,N,N,N,Nâ³,Nâ³-Hexamethylguanidinium chloride (readily obtainable by dimethylamine and N,N,N,N-tetramethylchloroformamidinium chloride derived from tetramethylurea and phosgene) forms tris(dimethylamino)methane in 53% yield under the exposure of the reducing agent sodium bis(2-methoxyethoxy)aluminium hydride (Red-Al).
Sodium hydride and trimethyl borate reduce N,N,N,N,Nâ³,Nâ³-hexamethylguanidinium chloride in 80% yield to tris(dimethylamino)methane.
Tris(dimethylamino)methane is a clear, colorless or pale yellow liquid with a strong ammoniacal odor. The compound is freely miscible with many non-polar aprotic and water-free solvents. However, when heated tris(dimethylamino)methane reacts with protic solvents (such as water or alcohols) but also with weak CH-acidic substances, such as acetone or acetonitrile.
Upon heating to 150âÂÂ190 ðC decomposition occurs with the formation of tetrakis(dimethylamino)ethene, a strong electron donor.
Tris(dimethylamino)methane dissociates into N,N,N,N-tetramethylformamidinium cations and dimethylamide anions, which abstract protons from CH- and NH-acidic compounds. The anions thus formed add to the formamidinium cations which in turn eliminate dimethylamine and react to form dimethylaminomethylene compounds (= CHâÂÂN(CH<sub>3</sub>)<sub>2</sub>) or amidines by aminomethyleneation.
Reaction to form a methyl ñ-cyano-ò-dimethylaminoacrylate:
Reaction to form N,N-dimethyl-N-p-nitrophenylformamidine:
Aminomethylenation provides intermediates for the synthesis of heterocycles such as pyrimidines, pyrazoles, 1,4-dihydropyridines and indoles.
N,N,N,N-Tetramethylselenourea is accessible by the extended heating of tris(dimethylamino)methane with selenium in xylene, bis(dimethylamino)carbene is suggested as an intermediate.