Characteristic Features of the Synthesis of 2,1,3-Benzothiadiazole-Substituted 1,3-Iminophosphine and Platinum Complex of this Compound

In an attempt to synthesize a new iminomethylphosphine, tBuC(Ph2P)=N-Btd (Btd = 2,1,3-benzothiadiazole) by a three-step procedure including (1) NH2-Btd + tBuC(=O)Cl → tBuC(=O)NH-Btd; (2) tBuC(=O)NH-Btd + SOCl2 → tBuC(Cl)=N-Btd; (3) tBuC(Cl)=N-Btd + Ph2PSiMe3 → tBuC(Ph2P)=N-Btd, it was found that the second step is accompanied by the chlorination of the carbocycle in the benzothiadiazole moiety. The reaction of the imidoyl chloride tBuC(Cl)=N-(7-Cl-Btd) formed in this reaction with Ph2PSiMe3 gave 1,3-iminomethylphosphine tBuC(Ph2P)=N-(7-Cl-Btd) (PC=N). The byproducts formed in this step include 1,3-aminomethylphosphine oxide tBuC{Ph2P(O)}NH-(7-Cl-Btd) (POCN) and (Ph2POx)2,, resulting from partial oxidation and hydrolysis. The reactions of PC=N and POCN with [Pt(COD)Cl2] (COD = 1.3-cyclooctadiene) were studied. In the case of PC=N, the reaction affords the [Pt(PC=N)2Cl2] complex. In the latter case, cleavage of the P–C bond in POCN takes place, and [PtCl2(Ph2POH)2](POCN) and [Pt(CH3CN){tBuC-NH-(7-Cl-Btd)}Cl]. are isolated from the reaction mixture. The structures of the new compounds were established by single-crystal X-ray diffraction (tBuC(Cl)N-(7-Cl-Btd)), 2335152 (POCN · Et2O), 2335149 (Ph2POx)2, 2335153 ([Pt(PC=N)2Cl2]), 2335154 ([PtCl2(Ph2POH)2](POCN)), 2335151 ([Pt(CH3CN)(tBuC-NH-(7-Cl-Вbtd))Cl]).