SPIRO[2H-1-BENZOPYRAN-2,4'-PIPERIDIN]-4(3H)-ONE, 6-CHLORO- synthesis

4synthesis methods

Product Name:SPIRO[2H-1-BENZOPYRAN-2,4'-PIPERIDIN]-4(3H)-ONE, 6-CHLORO-
CAS Number:792895-79-5
Molecular formula:C13H14ClNO2
Molecular Weight:251.71

TERT-BUTYL 6-CHLORO-4-OXOSPIRO[CHROMAN-2,4'-PIPERIDINE]-1'-CARBOXYLATE

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SPIRO[2H-1-BENZOPYRAN-2,4'-PIPERIDIN]-4(3H)-ONE, 6-CHLORO-

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Yield:792895-79-5 88%

Reaction Conditions:

Stage #1: tert-butyl-6-chloro-4-oxospiro[chromanone-2,4'-piperidine]-1'-carboxylatewith trifluoroacetic acid in dichloromethane; for 24 h;
Stage #2: with sodium hydroxide in chloroform;water; pH=~ 12;

Steps:

23

A solution of 1-(5-chloro-2-hydroxyphenyl)ethanone (ASDI Inc., Newark, DE) (103.9 g, 0.609 mol), tert-butyl 4-oxopiperidine-1-carboxylate (2; 121.2 g, 0.609 mol) and pyrrolidine (50.8 mL, 0.609 mol) in methanol (500 mL) was stirred for 24 h, and then the precipitated crystals were separated by filtration and washed with hexane/ethyl acetate (9:1) mixture. Then hexane (150 mL) was added, and the obtained mixture was refluxed and then filtered. The separated crystals were dried to give N-Boc-6-chlorospiro- [chromene-2,4'-piperidin]-4(3H)-one in 72% (153 g) yield. Neat trifluoroacetic acid (80 mL) was added to a solution of N-Boc-6-chlorospiro[chromene-2,4'- piperidin]-4(3H)-one (50 g, 0.14 mol) in dichloromethane (300 mL). The mixture was stirred for 24 hours and then evaporated. Water (200 mL) and chloroform (200 mL) were added to the residue, and the obtained mixture was made alkaline with 19 N NaOH to about pH 12. The product was extracted with chloroform. The extract was passed through a thin layer of SiO₂ and Na₂SO₄ to give 6- chlorospiro[chromene-2,4'-piperidin]-4(3H)-one in 88% (30.8 g) yield, 252/254 (ES+).

References:

WO2008/65508,2008,A1 Location in patent:Page/Page column 22-23

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References

79099-07-3 Synthesis

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79099-07-3 Synthesis

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References