Thioureas from isothiocyanates

Thioureas give thioxo analogues of a variety of the above syntheses (52JOC542), although these thioxo products are usually prepared from isothiocyanates (Section 2.15.5.2.1). Examples are known in the pyrido-[2,3-[Pg.225]

N,N Disubstituted thioureas from secondary amines and silicon tetra-isothiocyanate, 46, 69 N,N-Disubstituted ureas from secondary ammes and silicon tetraiso-cyanate, 46, 69... 

Organic synthesis 13 [OS 13] Thiourea from phenyl isothiocyanate and cyclohexylamine... 

OS 13] [R 17] [no protocol] Using a micro mixer/commercial tube reactor, the synthesis of a thiourea from phenyl isothiocyanate and cyclohexylamine at 0 °C was carried out [85] (see a more detailed description in [42]). A single mixing device connected to a stainless-steel tube of about 10 m length and 0.25 mm diameter was used. The feasibility of performing a nearly spontaneous reaction could be shown. 

Dipolar cycloaddition reactions, of nitrones to olefins, 46, 97 of 3-phenylsydnone, 46, 98 Dispiro[5.1.5.1]tetradecane-7,14-dione, photolysis to cyclohexylidene-cyclohexane, 47, 34 preparation from cyclohexanecarbonyl chloride and triethylamine, 47, 34 Displacement of bromine from 1-bromo-2-fluoroheptane to give 2-fluoro-heptyl acetate, 46, 37 N,N -Disubstituted formamidines from triethyl orthoformate and primary amines, 46, 41 N,N-Disubstituted thioureas from secondary amines and silicon tetra-isothiocyanate, 45, 69 N,N-Disubstituted ureas from secondary amines and silicon tetraiso-cyanate, 45, 69... 

N,N-Disubstituted thioureas from secondary amines and silicon tetra-isothiocyanate, 46, 69... 

N-Mono- and N,N-disubstituted UREAS AND THIOUREAS, 45, 69 N-Monosubstituted thioureas from primary amines and silicon tetra-isothiocyanate, 45, 69 N-Monosubstituted ureas from primary amines and silicon tetraisocyan-ate, 45, 69... 

Isothiocyanate sulfides, (RNCS)2S, arise similarly from isothiocyanates by successive treatment with bromine in anhydrous chloroform, and hydrogen sulfide158,160 or ethanol.161 The phenyl homolog has also been obtained by the action of thiophosgene on diphenyl-thiourea,162 or aluminum chloride on phenyl isothiocyanate.103... 

Oligothioureas have been prepared on cross-linked polystyrene from Boc-pro-tected oaminoisothiocyanates, which were synthesized in solution from symmetric diamines [258]. The formation of thioureas from support-bound amines and isothiocyanates is a rather sluggish reaction (e.g. 3 d, 45 °C, mean coupling yield 90% [258]), and only short oligomers can be prepared using this strategy. 

Formation of thiourea linkages from isothiocyanates and e-amino groups of lysine residues in proteins... 

A similar reaction has been more recently described by other authors. Thioureas 89—the intermediates in the preceding reaction—were prepared from isothiocyanate 88 and amines. Benzo-TAs 90, which contain substituents on the exocyclic nitrogen atom, were obtained (92MI1) (Scheme 28). 

With the use of a micromixer/commercial tube reactor, the synthesis of a thiourea from phenyl isothiocyanate and cyclohexylamine at 0 °C was carried out [25]. 

The amino alcohols d-50 and l-50 were converted into d-408 and l-408 via coupling with isothiocyanate 7 to give the thiourea d-405 (93%), which was similarly converted into the cyclic isourea d-406 100%) (Scheme 53).98 Conventional O-debenzylation afforded the trehazolin analogue d-407 (96%), which was further characterized as the octa-iV,O-acetyl derivative d-408. Likewise, the diastereoisomer l-407 was synthesized in 91% overall yield by similar reaction sequence, starting from the l-405 (97%) obtained from isothiocyanate 7 and aminotetrol l-50. 

Simple addition, in which both fragments of the NH molecule enter the new compound as in the preparation of alkanolamines from alkylene oxides, aminonitriles from unsaturated nitriles, and ureas and thioureas from isocyanates and isothiocyanates. 

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