Sodium Chloride → 3-Benzyl-1 oxa-2,8-diazaspiro[4.5]dec-2-ene-8-carboxylic acid tert-butyl ester

Compound W (3.33 g, 20 mmol), dissolved in abs. DCM (15 ml), was added dropwise at 0° C. within 10 min to a solution of compound B (2.81 g, 14.3 mmol in abs. DCM (22 ml)). A solution of triethylamine (11.2 ml, 80 mmol) in abs. DCM (10 ml) was added to this mixture at 0° C. within 10 min. As the reaction was highly exothermic, cooling was carried out with a mixture of ice and sodium chloride. The reaction mixture was stirred for 16 h at RT. For working up the mixture, DCM (15 ml) and water (45 ml) were added and the mixture was stirred for 15 min. After separation of the phases, the aqueous phase was extracted with DCM (2×45 ml). The phases were separated. The organic phase was washed successively with 10% citric acid solution (2×30 ml) and sat. NaCl solution (30 ml). The organic phase was dried and concentrated (5.3 g, brown oil). The residue was separated by chromatography [silica gel 60 (180 g); cyclohexane/EtOAc 7:1 (1,200 ml); 5:1 (900 ml)]. The desired product X was obtained in a yield of 681 mg (11%).

1. temperaturecooling
2. additionwere added
3. stirringthe mixture was stirred for 15 min
4. customAfter separation of the phases
5. extractionthe aqueous phase was extracted with DCM (2×45 ml)
6. customThe phases were separated
7. washThe organic phase was washed successively with 10% citric acid solution (2×30 ml) and sat. NaCl solution (30 ml)
8. customThe organic phase was dried
9. concentrationconcentrated (5.3 g, brown oil)
10. customThe residue was separated by chromatography [silica gel 60 (180 g); cyclohexane/EtOAc 7:1 (1,200 ml); 5:1 (900 ml)]

ORD record

ord-5e17e3200df649e4a36ead3336ae956f

Source dataset

uspto-grants-2014_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08772307B2