Hydrazine hydrate (1:1) → HCID 68675033、化合物

To a suspension of 1-cyclohexylmethyl-7-chloro-1H-indole-3-carboxylic acid (as prepared in Example 16; (2.0 g, 6.8 mmol) in dichloromethane (60 ml) was added oxalyl chloride (1.2 ml, 14 mmol) and the reaction stirred for 2 h and left to stand overnight. The solvent and excess reagent was removed in vacuo. The resulting residue was dissolved in dichloromethane (10 ml) and added dropwise to a cooled solution (ice/methanol bath) of hydrazine hydrate (1.7 ml, 34 mmol) in diethyl ether (60 ml) over 5 mins. The reaction mixture was then stirred for a further 40 mins before being reduced to half its volume in vacuo and filtered. The filtrate was concentrated further and the resulting precipitate filtered. The precipitates were combined and dried in vacuo to afford 1-cyclohexylmethyl-7-chloro-1H-indole-3-carboxylic acid hydrazide (2.3 g, 7 mmol).