Potential long-acting contraceptive agents: Esters and ethersof testosterone with α-and/or β-chain branching

Highly efficient, solvent-free esterification of testosterone promoted by a recyclable polymer-supported tosylic acid catalyst under microwave irradiation

“…[26][27][28][29] Since it is well-recognized that relatively high doses of exogenous testosterone suppress spermatogenesis, there have been reports on the synthesis and experimental use of various testosterone derivatives in male hormonal contraception. [30][31][32][33][34] In addition, because of high anabolic efficiency of testosterone, a plethora of its derivatives are unfortunately extensively employed in non-medical use, e.g. as athletic performance-enhancing drugs in sport doping trades.…”

“…Consequently, a plethora of chemical protocols have been explored to provide routes toward process improvements of an esterified variants of testosterone. Amongst the most common methods are those which employ activated carboxylic acid derivatives such as acid anhydrides or acid chlorides in the presence of basic amines such as triethylamine (Et 3 N), 40,41 pyridine (Py), [42][43][44][45][46][47][48][49] 4-(dimethylamino)pyridine (DMAP) 50 and/or N,Ndimethylaniline (DMA) 51 as well as a binary mixture of those amines (Py/DMAP), [52][53][54][55][56][57] respectively. A similar kind of conversions have been reported by Yadav et al 58 using potassium fluoride on alumina (KF-Al 2 O 3 ) as a solid base catalyst.…”