反应详情

温度

100 °C

To a stirred mixture of 4,7-Dichloroquinazoline (800 mg, 4 mmol) and piperidine-1,4-dicarboxylic acid 1-tert-butyl ester 4-methyl ester (1.2 g, 5.2 mmol), as prepared in Example 1a, in a sealed vial at rt was added drop-wise a 1 M solution of LiHMDS in THF (6 mL, 6 mmol). The mixture was stirred at rt overnight. It was then quenched with aqueous NaH2PO4 and the mixture was extracted with DCM. The DCM layer was drawn off, washed with water, brine, dried over anhydrous MgSO4, filtered and concentrated in vacuo to obtain 2.2 g (>100%) of crude 4-(7-chloro-quinazolin-4-yl)-piperidine-1,4-dicarboxylic acid 1-tert-butyl ester 4-methyl ester (3a) as a yellow semi-solid which was used as such for the next step. Solid KOH (224 mg, 4 mmol) was added to a suspension of 4-(7-chloro-quinazolin-4-yl)-piperidine-1,4-dicarboxylic acid 1-tert-butyl ester 4-methyl ester (3a; 41 mg, 0. 1 mmol) in a 1:1 mixture of dioxane and water (1 mL). The mixture was stirred at 100° C. for 3 h. It was then cooled to rt and concentrated in vacuo. The residue was dissolved in DCM and washed with water, brine, dried over anhydrous MgSO4, filtered and concentrated in vacuo to obtain crude 4-(7-chloro-quinazolin-4-yl)-piperidine-1-carboxylic acid tert-butyl ester (3b). This was dissolved in 2 mL of 3M HCl/MeOH was stirred at rt for 1 h and then concentrated in vacuo to obtain crude 4-(7-chloro-quinazolin-4-yl)-piperidine (3c) as a di-HCl salt.

1. temperatureIt was then cooled to rt
2. concentrationconcentrated in vacuo
3. dissolutionThe residue was dissolved in DCM
4. washwashed with water, brine
5. dry with materialdried over anhydrous MgSO4
6. filtrationfiltered
7. concentrationconcentrated in vacuo