Hexane → HCID 67214738, compound

Participants

Reaction Steps

In a variation of Example 8, Step A, a solution of 5.69 g (36.7 mmol) of 3-amino-4-carbethoxypyrazole and 6.00 g (30.6 mmol) of (mesitylmethylene)malononitrile (Intermediate 3) in 34 mL of anhydrous pyridine was stirred at reflux under air for 6 days. The dark solution was cooled and concentrated in vacuo. The residue was flash chromatographed on silica gel (gradient elution with 20-50% ethyl acetate in hexane) to give the crude product as a dark solid contaminated with another regioisomer. This material was dissolved in diethyl ether containing a little ethyl acetate. Addition of hexane precipitated a dark, tacky solid. This semisolid was collected and redissolved in 9:1 dichloromethane:methanol. Addition of hexane resulted in precipitation. The precipitate was collected on a filter and dried to give the title compound as a yellow solid. LC-MS 350 (M+1).

Provenance & Evidence