Acetic Acid → HCID 66869262, compound

Participants

Reaction Conditions

Reaction Steps

Add dropwise a solution of N-tert-butyl-N′-(4-fluorobenzylidene)hydrazine (Tetrahedron, 1986, 42, 4223-4234) (8.4 g, 43.2 mmol) in acetonitrile (43 mL) to a well stirred mixture of ethyl propiolate (4.4 mL, 43.2 mmol) and acetic acid (37 mL, 648 mmol) at RT. Warm the mixture at 50° C. for 2 days and at 60° C. for 1 day. Cool at RT and dilute with dichloromethane (250 mL). Wash the mixture with water (50 mL), a saturated aqueous solution of Na2CO3 (2×50 mL), dry (MgSO4), concentrate and purify (Biotage system eluting with CH2Cl2). Dissolve the yellow solid obtained in dichloromethane (43 mL) and acetic acid (37 mL) and bubble a stream of O2 at RT for 10 days. Dilute the mixture with dichloromethane (100 mL) and wash with a saturated aqueous solution of Na2CO3 (2×50 mL), dry (MgSO4) and concentrate and purify (Biotage system eluting with CH2Cl2) to provide the desired compound as yellow solid (6.4 g, 51% yield).

Provenance & Evidence