Total deprotection of N,N′-bis(tert-butoxycarbonyl)guanidines using SnCl4

Guanidines from ‘toxic substances’ to compounds with multiple biological applications – Detailed outlook on synthetic procedures employed for the synthesis of guanidines

“…Microwave-assisted synthesis of highly functionalized guanidines on soluble polymer support © 2012 Elsevier Ltd. 51 Synthesis of novel functionalized guanidines and their different reactions have also been extensively carried out by many research groups, employing different approaches. Including the synthesis of dicarbethoxyguanidine, [103] nitroguanidine, [104] nitrotriarylguanidines, [105] N 1 -(6 -Methoxy-8-quinolylaminoalkyl-)guanidines, [106] 1-(Alky1amino)-guanidines, [107] N-alkyl-N'-carboalkoxy guanidines, [108] guanidino diesters, [109] N-guanidino-modified arginines, [110] radioabeled guanidines, [111] pyranosyl nucleosides with guanidine functionality, [112] phosphinyl guanidines, [113] guanidinium chlorides, [114] phase transfer catalyzed alkylation of guanidines, [115] N-triflyl guanidines, [116] cyclic guanidines, [117], [70] monocyclic guanidines, [118] bicyclic guanidines, [25], [119] tricyclic guanidines, [120] tetracyclic guanidines, [121] macrocyclic guanidines, [122] and polycyclic guanidines. [123] …”

Non‐Nucleoside HIV‐1 Reverse‐Transcriptase Inhibitors. Part 10

“…Compounds 7 [10], 8a -8d [11], 9a -9d [12], and 10a -10e and 11 [13] were prepared as described in the literature [13]. General Procedure for the Preparation of 6a -6m.…”

“…Treatment of 7 with the appropriate amines in the presence of HgCl 2 and Et 3 N in anhydrous DMF provided the protected guanidines 8a -8d in 50 -90% yield [11]. The Boc groups in 8a -8d were smoothly removed upon treatment with SnCl 4 in anhydrous AcOEt, which led to compounds 9a -9d in 80 -95% yield [12]. Their condensation with b-keto esters 10a -10e [13] in the presence of EtONa/EtOH under N 2 atmosphere finally afforded the desired target compounds 6a -6m in 20 -80% yield.…”

A versatile synthesis of 2‐amino‐4H‐pyrido[1,2‐a][1,3,5]triazin‐4‐ones from 2‐aminopyridines

“…On our part, with the aim of building guanidine libraries of medicinal chemistry interest, we studied the total deprotection of bis Boc-guanidines using SnCl 4 [23], and also their conversion to N-Boc-amidinoureas by reaction with amines [24] (Scheme 2).…”

“…On our part, with the aim of building guanidine libraries of medicinal chemistry interest, we studied the total deprotection of bis Boc-guanidines using SnCl 4 [23], and also their conversion to N-Boc-amidinoureas by reaction with amines [24] (Scheme 2). Furthermore, considering that no works have yet taken advantage of these new methods to produce cyclic polysubstituted guanidines by direct ring closure of suitable substrats, we studied the synthesis of compounds of the title, starting from 2-aminopyridines.…”