Thiourethans amines

The same regiochemistry is observed when nitroimidazole (48-2, 48-3) acts as a nucleophile in unionized form. Thus, the reaction of a compound with benzoyl-aziridine (49-1) in the presence of boron trifluoride probably involves an initial salt formation with an amide attack by the imidazole results in a ring opening and the formation of the alkylated product (49-2) the free primary amine (49-3) is obtained on basic hydrolysis. Acylation of the primary amine with methyl thiochloroformate gives the corresponding thiourethane, carnidazole (49-4) [52]. 

The isocyanate, SF5NCO, is easily hydrolyzed to SF5NH2 and C02, whereas SF5NCS is hydrolytically very stable. Both compounds undergo addition reactions with substrates containing easily replaceable hydrogen atoms, i.e., alcohols, thiols, and amines. With alcohols (thiols) the isocyanate and isothiocyanate give urethanes and thiourethanes, respectively. 

In accord with the special reactivity of a dithiocarboxylate moiety, 0,5-dialkyl dithiocarbonates, ROCSSR, yield 0-alkyl thiourethanes, ROCSNR 2, on addition of amines. Similarly, trithiocarbo-nates, (RS)2CS, yield thioureas. - ... 

The reaction of ethyl 3-isothiocyanatopyridine-2-carboxylate with ethanol at reflux temperature results in the formation of the corresponding thiourethane which, by reaction with amines in anhydrous ethanol, can be converted into pyrido[3,2-c/]pyrimidin-4(3//)-one derivatives, partly with subsequent substitution of the sulfanyl group.428... 

Amines from thiourethans N-Detosylation s. a. Amines from sulfonic acid amides —, oxidative 20, 562 suppl. 20 —, preferential 16, 367 0-Detosylation of nucleosides 18, 8... 

Amine derivatives—amt. phlorethyl 678 phosphonyl 678 sulfenyl 677 sulfonyl 675 toluenesulfonyl 676 thiourethane-type 687, 688 trialkylsilyl 691 trifluoroacetyl 672 triphenylmethyl 690 urethane-type 682-687... 

Later work on the reactions of nickel xanthate complexes, [Ni(S2COR )2], with secondary amines revealed the formation of thiourethanes, R2NC(S)OR, together with nickel bis(dithiocarbamate) complexes (Fig. 26). Both are product of nucleophilic attack of the amine at the -hybridized carbon, the difference between the two pathways being whether the alkoxide or metal-sulfide moieties act as the leaving group (225). 

In the presence of catalytic amount of a base (such as triethylamine (NEtj)), thiols are deprotonated to thiolate anions, which react with isocyanates forming thiourethanes. The thiol-isocyanate reaction is fast and proceeds readily without any side product even in the presence of water, alcohol, or amines. The most common base used for this reaction is l,5-diazabicyclo(4.3.0)non-5-ene (DBN). The reaction has the potential to be used more often as a very effective conjugation method (Scheme 1.14). 

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