Iron → Fe Ac2O AcOH

Participants

Reaction Conditions

Reaction Steps

A mixture of spray-dried KF (138 mg, 2.3 mmol), intermediate 9 (100 mg, 0.23 mmol) and catalytic amount of 18-crown-6 (20 mg) in dry DMSO (4 mL) was stirred at 100-110° C. for 15 min. Work-up of the reaction mixture as described in example 1 gave the residue. This residue was dissolved in a mixture of AcOH and Ac2O (5 mL, 1:1) and added iron powder (193 mg, 3.44 mmol) at rt. The mixture was stirred at 85-90° C. for 15 min and work-up of the reaction mixture as described in example 2 gave the product as an off-white color solid (39 mg, 65%), mp 236-238° C.; 1H NMR (400 MHz, DMSO-d6): δ 12.53 (1H, br s), 9.92 (1H, br s), 8.84 (1H, t, J=6 Hz), 8.11 (1H, t, J=7.6 Hz), 7.67-7.73 (2H, m), 3.92 (2H, d, J=5.2 Hz), 2.13 (3H, s); LC-MS (negative ion mode): m/z 253 (M−H)−.

Provenance & Evidence