Bromotrimethylsilane → HCID 58427991, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of carbonic acid ethyl ester 8-methoxy-1-methoxymethoxy-2-oxo-3-(2,4,6-trimethyl-phenyl)-1,8-diaza-spiro[4.5]dec-3-en-4-yl ester (compound P1 ii.7 obtained in analogy to preparation example 11, step 6) (1.0 g, 2.23 mmol) in bromotrimethylsilane (4.33 ml, 5.12 g, 33.44 mmol) under argon atmosphere was added 3 {acute over (Å)} molecular sieves (0.5 g) and the reaction mixture was stirred at 75° C. overnight. The mixture was diluted with dichloromethane, filtered, the filtrate evaporated, the residue triturated with cold diethyl ether, filtered and dried. The crude product was purified by chromatography on silica gel (gradient dichloromethane→dichloromethane/methanol 20:1→10:1). Yield: 580 mg of carbonic acid ethyl ester 1-hydroxy-8-methoxy-2-oxo-3-(2,4,6-trimethyl-phenyl)-1,8-diaza-spiro[4.5]dec-3-en-4-yl ester (compound P1ii.11) as a white solid, mp 154-155° C.

Provenance & Evidence