An amide (/ˈæmaɪd/ or /ˈæmɪd/ or /ˈeɪmaɪd/), also known as an acid amide, is a compound with the functional group RnE(O)xNR′2 (R and R′ refer to H or organic groups). Most common are carboxamides (organic amides) (n = 1, E = C, x = 1), but many other important types of amides are known, including phosphoramides (n = 2, E = P, x = 1 and many related formulas) and sulfonamides (E = S, x = 2). The term amide refers both to classes of compounds and to the functional group (RnE(O)xNR′2) within those compounds.
Amide can also refer to the conjugate base of ammonia (the anion H2N−) or of an organic amine (an anion R2N−). For discussion of these "anionic amides", see Alkali metal amides.
The remainder of this article is about the carbonyl–nitrogen sense of amide....LESS