Pyridine → Dicyclohexylcarbodiimide

Participants

Reaction Steps

The nitro compound (xlv) can be reduced to the corresponding amine (xlvi) by 1) hydrogenation in the presence of a catalyst such as Raney nickel in a solvent such as methanol, ethanol or ethyl acetate at room temperature for a period of 1-24 hours; 2) chemical reduction such as SnCl2 in a solvent such as water at a temperature of 25-100° C. for a period of 1-24 hours. The amine (xlvi) can be alkylated with 1) an alkyl halide in the presence of a base such as potassium carbonate, triethylamine or sodium methoxide in an appropriate solvent such as acetonitrile, ethanol or chloroform at a temperature of 25-100° C. for a period of 1-24 hours; 2) an aldehyde in the presence of a reducing agent such as sodium cyanoborohydride in a solvent such as methanol, dichloromethane or a mixture thereof at a temperature of 25-80° C. for a period of 1-72 hours to give compound (xlvii). Reaction of the primary (R9=H) or secondary amine (xlvii) with a reactive aryl chloride such as chloronitrobenzene, chloropyridine or chloropyrimidine with or without a base such as potassium carbonate, triethylamine or sodium hydride in an appropriate solvent such as THF, DMF or dioxane at a temperature of 25-120° C. for a period of 1-24 hours give the arylamino compound (xlviii). Further alkylation of (xlvii) with an arylalkyl halide with or without a base such as potassium carbonate, triethylamine or sodium hydride in an appropriate solvent such as acetonitrile, THF or DMF at a temperature of 25-100° C. for a period of 1-24 hours give the amino compound (xlix). Reaction of amino compound (xlvii) with sulfonyl chloride in the presence of a base such as triethylamine, pyridine or potassium carbonate in a solvent such as dichloromethane, chloroform or benzene at a temperature of 25-100° C. for a period of 1-24 hours gives the sulfonamide (1). Acylation of the amine (xlvii) with 1) an acid chloride in the presence of a base such as triethylamine, pyridine or potassium carbonate in an appropriate solvent such as dichloromethane, THF or DMF at a temperature of 25-100° C. for a period of 1-16 hours; 2) an carboxylic acid with a coupling reagent such as DCC or EDC in an appropriate solvent such as chloroform or DMF for a period of 1-16 hours gives the corresponding amide (li). Reaction of the amine (xlvii) with an isocyanate in a solvent such as benzene, chloroform or dioxane at a temperature of 25-120° C. for a period of 1-24 hours gives the urea compound (lii).

Provenance & Evidence