Thioamide
A thioamide (rarely, thionamide, but also known as thiourylenes) is a
organyl groups or hydrogen). Analogous to amides, thioamides exhibit greater multiple bond character along the C-N bond, resulting in a larger rotational barrier.[1]
Examples
A well-known thioamide is
heterocyclic chemistry
.
Thioamides or anti-thyroid drugs are also a class of
thyrotoxicosis
.
Preparation and structure
Thioamides are typically prepared by treating amides with phosphorus sulfides such as phosphorus pentasulfide, a reaction first described in the 1870s.[2][3][4] Alternative routes include the use of Lawesson's reagent[5] or the reaction of nitriles with hydrogen sulfide:
The
Willgerodt-Kindler reaction also gives benzylthioamides.[6]
The C(R)(N)(S) core of thioamides is planar. Using thioacetamide as representative: the C-S, C-N, and C-C distances are 1.68, 1.31, and 1.50 Å, respectively. The short C-S and C-N distances indicate multiple bonding.[7]
Thioamides in biochemistry and medicine
Thioamides are also a class of
thyrotoxicosis
.
Thioamides have been incorporated into peptides as
SAR). Analogues of peptides can also be used as drugs with an improved oral bioavailability
.
Thioamides inhibit the enzyme thyroxine (T4), thereby blocking uptake of iodotyrosines from the colloid
. They also block iodine release from peripheral hormone. Maximum effects occur only after a month, since hormone depletion is caused by reduced synthesis, which is a slow process.
References
- .
- .
- ^ Gompper, R.; Elser, W. (1973). "2-Methylmercapto-N-Methyl-Δ2-Pyrroline". Organic Syntheses; Collected Volumes, vol. 5, p. 780.
- ^ Schwarz, George (1955). "2,4-Dimethylthiazole". Organic Syntheses; Collected Volumes, vol. 3, p. 332.
- ^ Shabana, R.; Scheibye, S.; Clausen, K.; Olesen, S.O.; Lawesson, S.-O. (1980). "Studies on organophosphorus compounds XXXI. Synthesis of thiolactams and thioimides". Nouveau Journal de Chimie. 1980 (4): 47.
- ^ Rolfs, Andreas; Liebscher, Jürgen (1998). "3-Morpholino-2-Phenylthioacrylic Acid Morpholide and 5-(4-Bromobenzoyl-2-(4-Morpholino)-3-Phenylthiophene". Organic Syntheses; Collected Volumes, vol. 9, p. 99.
- doi:10.1039/B109353C.
- .