Tetrazoles, 5-mercapto

Tetrazole-5-thiones Anhydro-5-mercapto-l,2, 4-tetrazolium Hydroxides) (295)... 

An interesting cleavage of a carbon-sulfur bond in benzylic and allylic sulfides derived from 5-mercapto-l -phenyl-1 //-tetrazole has been reported [326]. The overall reaction is an alkylation a to a carbonyl group. 

N—NfC2H4N4 mw 84.10 N 66.63% prisms (from eth) mp 36—37°. V sol in ethanol and w si sol in benz and hot eth insol in cold eth. Prepn is by heating a mixt of 1 -methyl-mercapto tetrazole with dil acid on a w bath, or by treating tetrazole with diazomethane. It forms expl salts Silver Salt-AgC2H3N4 white ndles mp, decompn at about 107°. Prepn is by adding an ethanolic soln of Ag nitrate to ethanolic 1-methyl tetrazole. Explds mildly when heated on a spatula at above 107°... 

KC3H3N402S mw 186.24 N 30.09% OB to C02 —30.07% cryst (from aq ethanol-eth). V sol in w si sol in ethanol insol in benz, chlf and eth. Prepn is by reacting K permanganate with 5-methyI-mercapto tetrazole. The salt explds violently when heated in an open flame Silver Salt. AgC2H3N402S mw 255.02 N 21.97% OB to C02 —21.96% amorph solid mp, explds on heating. Prepn is by treating an aq soln of the K salt with Ag nitrate Refs 1) Beil 26, 394 2) M. Freund T. 

This compd forms the expl 5,5-Lead-Bis-1r1 -Phenyl-5,5 -Mercapto Tetrazole. 

Methyl-5-mercapto-l,2,3,4-tetrazole (see Section 4.1) is a possible impurity and degradation product of moxalactam which can be determined by polarographic techniques (67). It is oxidized at a dropping mercury electrode in a pH 5.8 buffer. The concentration of the impurity tetrazole is proportional to the sum of the currents for the adsorption prewave and the main wave (half-wave potentials of about -0.20 V and -0.05 V vs SCE, respectively). 

Interestingly, although the thione form of neutral tetrazoles prevails, the alkylation and acylation of tetrazole-5-thione anions afford exclusively products of addition to the sulfur atom (cf. Section 6.07.7.5), suggesting that under specific conditions formation of the 5-mercapto form is possible. 

Thiones are oxidized, e.g., by iodine, to disulfides. Thus 5-mercapto-l,2,3,4-thiatriazole is converted into the disulfide 739 similar behavior is known in the tetrazole series. 

Amino-2-(l-subst.-lH-tetrazol-5-ylthio)-pyridine ergeben mit ethanolischer Salzsaure (Riick-fluB) in Abhangigkeit vomSubstituenten amTetrazol-Ring2-(subst.-Amino)- pyrido[3,2-d]-1,3-thiazole> oder 2-Mercapto-3-(l-subst.-lH-tetrazol-5-ylamino)-pyridine78 ... 

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