反应详情

Part A: 5-(Furan-2-yl)-3-trifluoromethyl-1-(2-carboxyl-4-methoxyphenyl)-1H-pyrazole: 3-Methoxy-6-aminobenzoic acid (23 g, 138 mmol) in conc. HCl (300 mL) was cooled to 0° C. and NaNO2 (11.4 g, 165 mmol) in H2O (50 mL) was added dropwise while the temperature of the reaction was maintained below 10° C. The reaction was stirred at or below 10° C. for 1 h, then SnCl2.H2O (92.3 g, 413 mmol) in conc. HCl (125 mL) was added dropwise. The reaction was allowed to thaw to ambient temperature and stirred for 3 h. The precipitate was filtered and air-dried then heated in a vacuum oven for 18 h. There was obtained 71.4 g of 3-methoxy-6-hydrazinobenzoic acid entrained with tin (II) salts.

1. temperaturewas maintained below 10° C
2. customthaw to ambient temperature
3. stirringstirred for 3 h
4. filtrationThe precipitate was filtered
5. customair-dried
6. temperaturethen heated in a vacuum oven for 18 h