Hydrochloric Acid → 2-(4-Acetyl-2-ethylphenylimino)-1-cyclopentyl-3-thia-1-azaspiro[4.4]nonane

Participants

Reaction Steps

To a solution of the 2-(4-carboxy-2-ethylphenylimino)-1-cyclopentyl-3-thia-1-azaspiro[4.4]nonane (Method D9a; 0.046 g, 0.128 mmol) in THF (10 mL) at −78° C. was added methyllithium (1.4 M in Et2O, 0.91 mL, 1.28 mmol). The reaction mixture was while allowed to gradually warm to room temp., then was stirred overnight. Trimethylsilyl chloride (0.5 mL) was added and the mixture was stirred at room temp. for 2 h, then a 1N HCl solution (2 mL) was added. The mixture was stirred for 0.5 h, then was treated with a saturated NaHCO3 solution (10 mL). The resulting mixture was extracted with EtOAc (4×20 mL), and the combined organic layers were washed with a saturated NaCl solution (30 mL), dried (Na2SO4) and concentrated under reduced pressure. The residue was purified by preparative TLC (10% EtOAc/hex) to give 2-(4-acetyl-2-ethylphenylimino)-1-cyclopentyl-3-thia-1-azaspiro[4.4]nonane as a white solid (0.032 g, 73%): mp 114-115° C.

Provenance & Evidence