Oxalyl chloride → 2-Ethyl-4-methoxybenzothiazole-7-carboxylic acid (4-cyano-2-methyl-2H-pyrazol-3-yl)amide

Participants

Reaction Steps

To a suspension of 2-ethyl-4-methoxybenzothiazole-7-carboxylic acid (0.1 g) in dichloromethane (10 ml) was added oxalyl chloride (1.0 ml) and dimethylformamide (1 drop). The reaction was stirred at room temperature for 16 hrs, and then the solvent was removed in vacuo to yield a brown solid residue. 5-Amino-1-methyl-1H-pyrazole-4-carbonitrile (0.1 g) was taken up in dichloromethane (10 ml) and sodium hexamethyldisilylamine (1.0M in tetrahydrofuran, 0.84 ml) was added. After 5 minutes the acid chloride was added and the reaction stirred at room temperature for 16 hrs. The solvent was removed in vacuo and the product purified by flash chromatography (eluent 50% ethyl acetatethexane-75% ethyl acetate/hexane) to yield the title compound as an off-white solid (0.088 g). TLC Rf 0.13 (50% ethyl acetate/hexane); Mpt 190-191° C.

Provenance & Evidence