Dimethyl (3,4-dichlorobenzoyl)carbonohydrazonodithioate, C10H10Cl2N2OS2, (D1), dibenzyl (3,4-dichlorobenzoyl)carbonohydrazonodithioate, C22H18Cl2N2OS2, (D2), dimethyl (3,4-dichlorobenzoyl)-1-methylcarbonohydrazonodithioate, C11H12Cl2N2OS2, (D3), 3,4-dichloro-N′-(1,3-dithiolan-2-ylidene)-N-methylbenzohydrazide, C11H10Cl2N2OS2, (D4), were synthesized as potential tuberculostatics. Compound (D1) (with two molecules in the asymmetric unit) was the only one showing tuberculostatic activity of the same range as the common drugs isoniazid and pyrazinamide. The molecular structures of the studied compounds depend on the substitution at the N atom adjacent to the carbonyl group. In the case of the unsubstituted derivatives (D1) and (D2), their central frames are generally planar with a twist of the 3,4-dichlorophenyl ring by 30–40°. Until now, coplanarity of the aromatic ring with the (methylene)carbonohydrazone fragment has been considered a prerequisite for tuberculostatic activity. TheN-methylated derivatives (D3) and (D4) show an additional twist along the N—C(=O) bond by 20–30° due to the spatial repulsion introduced by the methyl substituent.
(3,4-二氯苯甲酰基)二硫代碳酰肼二甲酸二甲酯,C10H10Cl2N2OS2,(D1);(3,4-二氯苯甲酰基)二硫代碳酰肼二甲酸二苄酯,C22H18Cl2N2OS2,(D2);(3、C11H12Cl2N2OS2, (D3)、3,4-二氯-N′-(1,3-二硫环戊-2-亚基)-N-甲基苯甲酰肼 C11H10Cl2N2OS2, (D4)。化合物 (D1)(不对称单元中有两个分子)是唯一具有与常用药物异烟肼和吡嗪酰胺相同范围的抗结核活性的化合物。所研究化合物的分子结构取决于与羰基相邻的 N 原子的取代情况。对于未取代的衍生物 (D1) 和 (D2),其中心框架一般为平面,3,4-二氯苯基环扭曲 30-40° 。迄今为止,芳香环与(亚甲基)碳腙片段的共面性一直被认为是抗结核活性的先决条件。由于甲基取代基带来的空间斥力,N-甲基化衍生物 (D3) 和 (D4) 沿着 N-C(=O)键显示出 20-30° 的额外扭曲。