Bis(trimethylsilyl)carbodiimide → N-(6-bromo-3'-isopropylspiro[chroman-2,1'-cyclopentane]-4-ylidene)cyanamide

Participants

Reaction Steps

To a solution of 6-bromo-3′-isopropylspiro[chroman-2,1′-cyclopentan]-4-one (250 mg, 0.776 mmol) in DCM (10 mL) was added TiCl4 (1.55 mL, 1 M in CH2Cl2) dropwise within 15 minutes at room temperature. After stirring for 1 h, N,N′-methanediylidenebis(1,1,1-trimethylsilanamine) (0.38 mL, 1.707 mmol) was added dropwise. The mixture was stirred at room temperature overnight and poured into ice-water (25 g). The aqueous layer was extracted with CH2Cl2, which was combined with the organic layer. The organic layer was dried and concentrated to give crude N-(6-bromo-3′-isopropylspiro[chroman-2,1′-cyclopentane]-4-ylidene)cyanamide (250 mg, 93%). 1H-NMR (CDCl3): 0.82 (m, 6H), 1.36 (m, 2H), 1.69 (m, 3H), 1.96 (m, 3H), 3.10 (d, 2H), 6.75 (m, 1H), 7.52 (m, 1H), 8.04 (d, 1H).

Provenance & Evidence