Synthesis and anti-TMV activity of novel N-（3-alkyl-lH-pyrazol-4- yl）-3-alkyl-4-substituted- 1H-pyrazole-5-carboxamides

In order to investigate the biological activity of novel bis-pyrazole compounds, a series of N-（3-alkyl-5-（N-methylcarbamyl）- 1H-pyrazol-4-yl）-3-alkyl-4-substituted-lH-pyrazole-5-carboxamides were designed and synthesized with ethyl 3-alkyl-lH-pyr- azole-5-carboxylate 1 as starting materials. N-Methyl-3-alkyl-4-amino-lH-pyrazole-5-carboxamides 6 were obtained from 1 via 5 steps. 3-Alkyl-4-substitued-lH-pyrazole-5-carboxyl chlorides 4a, 4b, lla, llb, llc or 12 were also obtained from 1 via several steps. Target compounds 7a-Tg were obtained after the reaction of 6 with the above 1H-pyrazole-5-carboxyl chlorides. Preliminary bioassay showed some compounds possessing good inactivation effect against TMV （tobacco mosaic virus）. Compound 7a showed higher activity superior to ningnanmycin at a concentration of 5.0 × 10^-4 g/mE and equal activity at 1.0 × 10^-4 g/mE; 7b and 7c showed equal activity to virazole both at concentrations of 5.0 × 10^-4 g/mE and 1.0 × 10^-4 g/mL.