Diisopropylamine → HCID 53839107, compound

Temperature

-40 °C

A solution of di-isopropylamine (4.38 g, 6.1 mL, 43.3 mmol) in anhydrous tetrahydrofuran (50 mL) was cooled to 0° C. with stirring. A solution of n-butyl lithium in hexanes (2.4 M, 17.3 mL, 43.3 mmol) was added dropwise; the resulting solution was stirred for 15 minutes. The reaction mixture was transferred via cannula to a suspension of methoxymethyl triphenyl phosphonium chloride (14.9 g, 43.3 mmol) in anhydrous tetrahydrofuran (100 mL), stirred at -20° C. The reaction mixture was stirred at -20° C. for 35 minutes, then it was cooled to -40° C. A solution of 1-benzyl-4-formylpiperidine (8 g, 39.4 mmol) in anhydrous tetrahydrofuran (50 mL) was added dropwise. The reaction mixture was warmed gradually to ambient temperature over 21 hours, then it was poured onto water (500 mL) mixed and extracted three times with ethyl acetate (500 mL). The combined organic layers were dried over magnesium sulfate, treated with decolorizing charcoal and filtered through Celite®. Solvent was removed in vacuo to give an orange oil. Column chromatography (ethyl acetate) gave the product as a mixture of E- and Z- isomers (Rf=0.41, 5.06 g):1H-NMR:7.4-7.2(m,5H), 6.3(d,0.6H,J=13), 5.8(d,0.4H,J=6), 4.65(dd,0.6H,J=13,6), 4.2(dd,0.4H,J=6,5), 3.5(s,1.2H), 3.45(s,1.8H), 2.9-2.7(m,2H), 2.5-2.3(m,1H), 2.1-1.3(m,7H); HR-MS:Calcd for C15H21NO:231.1623; Found:231.1633.

1. stirringthe resulting solution was stirred for 15 minutes
2. stirringstirred at -20° C
3. stirringThe reaction mixture was stirred at -20° C. for 35 minutes
4. temperatureThe reaction mixture was warmed gradually to ambient temperature over 21 hours
5. additionit was poured onto water (500 mL)
6. additionmixed
7. extractionextracted three times with ethyl acetate (500 mL)
8. dry with materialThe combined organic layers were dried over magnesium sulfate
9. additiontreated with decolorizing charcoal
10. filtrationfiltered through Celite®
11. customSolvent was removed in vacuo
12. customto give an orange oil
13. additionas a mixture of E- and Z- isomers (Rf=0.41, 5.06 g)

ORD record

ord-b827cebf39744366a52a49ad09a46c7c

Source dataset

uspto-grants-1992_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05116846