Cesium carbonate → 6-(4-tert-Butyl-cyclohexyloxy)-3,4-dihydro-1H-isoquinoline-2-carboxylic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

A mixture of 6-hydroxy-3,4-dihydro-1H-isoquinoline-2-carboxylic acid tert-butyl ester (1.1 g, 4.4 mmol), cesium carbonate (4.3 g, 13 mmol), and methanesulfonic acid 4-tert-butyl-cyclohexyl ester (2.2 g, 8.8 mmol) in t-BuOH (12 mL) and 2-butanone (6.0 mL) was heated in a sealed vial at 100° C. overnight. The mixture was partitioned between water and ether. The organic phase was washed with water, dried over MgSO4, filtered and concentrated. The residue was purified via a silica gel column eluted with EtOAc in hexanes from 0 to 30% to give white precipitate (1.0 g, yield: 58%). 1H NMR (400 MHz, CDCl3) δ 6.99 (d, 1H), 6.74 (dd, 1H), 6.67 (d, 1H), 4.49 (s, 2H), 4.07 (m, 1H), 3.61 (s, 2H), 2.78 (m, 2H), 2.18 (d, 2H), 1.85 (d, 2H), 1.48 (s, 9H), 1.37 (m, 2H), 1.18-1.00 (m, 3H), 0.87 (s, 9H).

Provenance & Evidence