Dichloromethane → 3-methyl-3-((R)-1-methyl-2-oxo-8-vinyl-1,2,3,5-tetrahydro-6-oxa-3,4,10,11 b-tetraaza-cyclopenta[b]phenanthren-10-yl)-azetidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Steps

A mixture of 3-((R)-8-iodo-1-methyl-2-oxo-1,2,3,5-tetrahydro-6-oxa-3,4,10,11b-tetraaza-cyclopenta[b]phenanthren-10-yl)-3-methyl-azetidine-1-carboxylic acid tert-butyl ester (0.3 g, 0.544 mmol), 4,4,5,5-tetramethyl-2-vinyl-1,3,2-dioxaborolane (0.838 g, 5.44 mmol), K2CO3 (0.15 g, 1.088 mmol) and Pd(dppf)Cl2.CH2Cl2 (0.044 g, 0.054 mmol) in dioxane (6 mL) and water (1 mL) was heated at 68° C. for 14 h. The reaction mixture was cooled to ambient temperature and the solvent was removed in vacuo. The residue was purified by column chromatography on silica gel (eluting with 10%˜100% EtOAc in petroleum ether) to give 3-methyl-3-((R)-1-methyl-2-oxo-8-vinyl-1,2,3,5-tetrahydro-6-oxa-3,4,10,11b-tetraaza-cyclopenta[b]phenanthren-10-yl)-azetidine-1-carboxylic acid tert-butyl ester (0.22 g, 90%) as yellow gum, which was used directly in the next step. LC/MS (Table 1, Method 25) Rt=0.892 min.; MS m/z: 452 [M+H]+.

Provenance & Evidence