Carbamate → 2-Nitrophenol

Participants

Reaction Steps

A solution of 7-[3-(4-Methyl-piperazin-1-yl)-propoxy]-4-piperidin-4-yl-quinazoline (3.654 g, 9.9 mmol), as prepared in the previous step, in 98:2 DCM/MeOH (15 mL) was added rapidly dropwise under air in 2 mL portions to an ice bath-chilled stirred mixture of (4-morpholin-4-yl-phenyl)-carbamic acid 4-nitro-phenyl ester hydrochloride (4.13 g, 10.9 mmol), as prepared in Example 66a, and dimethylethylamine (DMEA) (1.4 mL, 13 mmol) in 98:2 DCM/MeOH (20 mL). Residual quinazoline derivative was then transferred to the carbamate reaction mixture with 2×7 mL additional 98:2 DCM/MeOH. The resulting homogeneous dark amber solution was stirred for another 5 min, and the ice bath was then removed and the reaction stirred at “rt” for 1.5 hr. The homogeneous reaction solution was then directly applied to a silica flash column (79 mm diameter×6″ length) pre-equilibrated with acetone. The title compound was eluted with 1.5 L acetone→2 L 9:1 acetone/MeOH→2 L 9:1 acetone/MeOH/3% DMEA. The combined fractions were concentrated to afford the title compound contaminated with nitrophenol and DMEA, and this material was partitioned with DCM (100 mL) and 2 M aqueous K2CO3 (2×20 mL). The organic layer was dried (Na2SO4) and concentrated under high vacuum at 90° C. to afford the title compound as a lavender foam that was crushed to a powder [3.89 g, 70% over three steps from 4-(7-Fluoro-quinazolin-4-yl)-piperidine-1-carboxylic acid tert-butyl ester].

Provenance & Evidence