Aminal
{{Short description|Type of organic compound or group}}
{{Distinguish|Animal}}
In organic chemistry, an aminal or aminoacetal is a functional group or type of organic compound that has two amine groups attached to the same carbon atom: {{chem2|\sC(NR2)(NR2)\s}}. (As is customary in organic chemistry, R can represent hydrogen or an alkyl group).{{GoldBookRef|title=aminals|file=A00270}} A common aminal is bis(dimethylamino)methane, a colorless liquid that is prepared by the reaction of dimethylamine and formaldehyde:{{cite journal |doi=10.15227/orgsyn.059.0153|title=Regioselective Mannich Condensation with Dimethyl(Methylene)ammonium Trifluoroacetate: 1-(Dimethylamino)-4-methyl-3-pentanone
|first1=Michel|last1=Gaudry|first2=Yves|last2=Jasor|first3=Trung Bui |last3=Khac|journal=Org. Synth.|year=1979|volume=59|page=153}}
:{{chem2 | 2 (CH3)2NH + CH2O -> [(CH3)2N]2CH2 + H2O }}
Aminals are encountered in, for instance, the Fischer indole synthesis. Several examples exist in nature.{{cite book |editor=Saul Patai|doi=10.1002/9780470771679.ch5|chapter=Aminals|title=Amino, Nitroso and Nitro Compounds and Their Derivatives: Vol. 2|year=1982|last1=Duhamel|first1=Lucette|pages=849–907|isbn=9780470771679|series=PATAI'S Chemistry of Functional Groups}}
Physostigmin.svg|Physostigmine, a highly toxic cholinesterase inhibitor found in the Calabar bean.
Hodgkinsine.svg|Hodgkinsine, an alkaloid with antiviral, antibacterial and antifungal effects
5,10-methylenetetrahydrofolic acid.svg|5,10-Methylenetetrahydrofolate, an intermediate in one-carbon metabolism
Hexahydro-1,3,5-triazine ({{chem2|(CH2NH)3}}), an intermediate in the condensation of formaldehyde and ammonia, tends to degrade to hexamethylene tetraamine.
Cyclic aminals can be obtained by the condensation of a diamine and an aldehyde.Hiersemann, M. "Functions bearing two nitrogens" in Comprehensive Organic Functional Group Transformations II 2005, volume 4, 411-441. Edited by Katritzky, Alan R.; Taylor, Richard J. K. {{doi|10.1016/B0-08-044655-8/00075-1}} Imidazolidines are one class of these cyclic aminals.