Patent DE-102010020652-A1 (DE)
Title: New compound having tetrazine anion comprising 1,2,4,5-tetrazine-3,6-bis(thiolate) or 3-mercapto-6-sulfido-3H-1,2,4,5-tetrazin-2-ide, useful e.g. for producing 1,6-dihydro-(1,2,4,5)tetrazine-3,6-dithiol derivative
Inventor: RICHTER ANDREAS M
IPC: C07D257/08
Filed: 2010-05-14
Abstract: Compound having 1,2,4,5-tetrazine anion of type (I) having an elemental composition (Ib), comprising 1,2,4,5-tetrazine-3,6-bis(thiolate) or 3-mercapto-6-sulfido-3H-1,2,4,5-tetrazin-2-ide, in which the formal negative charge is balanced by at least one ionically or covalently bonded inorganic or organic group or a counterion, is new. Compound having 1,2,4,5-tetrazine anion of type (C 2N 4(S 2) 2->) (I) having an elemental composition (C 2N 4S 2) (Ib), comprising 1,2,4,5-tetrazine-3,6-bis(thiolate) or 3-mercapto-6-sulfido-3H-1,2,4,5-tetrazin-2-ide, in which the formal negative charge is balanced by at least one ionically or covalently bonded inorganic or organic group or a counterion, is new. Independent claims are also included for: (1) a 1,2,4,5-tetrazine complex of formula (II); (2) [1,2,4,5]tetrazine-3,6-dithiol or 1,6-dihydro-[1,2,4,5]tetrazine-3,6-dithiol (C 2H 2N 4S 2); (3) preparing the compound having anion (I); (4) preparing (II), comprising either dissolving or suspending 1,2,4,5-tetrazinan-2,6-dithione in a solvent comprising water, alcohols, preferably methanol, ethanol, n-propanol or isopropanol, formamide, acetonitrile, dimethylformamide, methylene chloride and/or chloroform, preferably water or mixture of water and lower chain alcohols, and converting the reaction mixture into (II) in presence of a base and an oxidizing agent, or reacting [1,2,4,5]tetrazine-3,6-dithiol or 1,6-dihydro-[1,2,4,5]tetrazine-3,6-dithiol with a base; (5) preparing [1,2,4,5]tetrazine-3,6-dithiol or 1,6-dihydro-[1,2,4,5]tetrazine-3,6-dithiol, comprising protonating 1,2,4,5-tetrazine complex of formula (IV) using a sufficiently strong organic or inorganic acid e.g. formic acid, acetic acid, oxalic acid, hydrochloric acid, sulfuric acid or phosphoric acid, in solid state or in a solvent e.g. water or lower alcohols; and (6) preparing 1,6-dihydro-[1,2,4,5]tetrazine-3,6-dithiol derivative of formula (III), comprising reacting (II) with an alkylating or arylating agent of formula (RX 6) in a substance or in a solvent, e.g. water, alcohols with 1-28C, preferably 1-4C, or dipolar aprotic solvents, e.g. acetonitrile or dimethylformamide, or under the conditions of phase transfer catalysis. X, Z : positively charged organic or inorganic group or metal, which are bonded covalently or ionically; X 5, Z 3organic or inorganic group or element, preferably alkali metal, alkaline earth metal or tetramethylammonium; R : aryl, preferably phenyl (substituted by at least one electron withdrawing groups e.g. NO 2or CN), 1-30C alkyl, preferably 1-28C alkyl or aralkyl, preferably benzyl (all optionally substituted by alkyl, aryl, alkoxy, CN, thio, sulfoxy, sulfone, NO 2, halo, preferably F, Cl or Br); and X 6Cl, Br or I, preferably Br or I (when R = alkyl), Cl (when R = substituted aromatics, methyl sulfate, triflate or toluenesulfonate that are sufficiently electronegative). [Image].