Ethyl 3-(4-pyridyl)-3-oxopropionate → (+/-) 2-(4-Oxo-2-pyridin-4-yl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-9-yl)-1H-isoindole-1,3(2H)-dione

To a suspension of 9.166 g (32.77 mmol) of (+/−) 2-(2-Amino-3,4,5,6-tetrahydropyridin-3-yl)-1H-isoindole-1,3(2H)-dione hydrochloride (1:1) in 50 mL of toluene was added sodium methanolate (freshly prepared from 0.754 g (32.77 mmol) of sodium in 10 mL of methanol and the reaction mixture was stirred at room temperature for 1 h. The mixture was evaporated to dryness, dissolved in 50 mL of toluene and 4.87 g (25.21 mmol) of ethyl 3-(pyridin-4-yl)-3-oxopropionate was added. The resulting solution was stirred under reflux for 12 h. The cooled solution was evaporated to remove solvent. The mixture was dissolved in dichloromethane, washed with a saturated aqueous solution of ammonium chloride, saturated aqueous sodium chloride, dried over sodium sulfate and evaporated to dryness. The residue was chromatographed on silica gel eluting with a mixture of dichloromethane/methanol/aqueous ammonia solution (29%) in the proportions 97/310.3 led to afford 3.2 g (34%) of the desired compound as a white powder.

1. customThe mixture was evaporated to dryness
2. dissolutiondissolved in 50 mL of toluene
3. stirringThe resulting solution was stirred
4. temperatureunder reflux for 12 h
5. customThe cooled solution was evaporated
6. customto remove solvent
7. dissolutionThe mixture was dissolved in dichloromethane
8. washwashed with a saturated aqueous solution of ammonium chloride, saturated aqueous sodium chloride
9. dry with materialdried over sodium sulfate
10. customevaporated to dryness
11. customThe residue was chromatographed on silica gel eluting with a mixture of dichloromethane/methanol/aqueous ammonia solution (29%) in the proportions 97/310.3

ORD record

ord-f18db96ce20a4903aef096d3b91a212e

Source dataset

uspto-grants-2012_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08148364B2