N-Butylaniline → HCID 22220234, compound

A solution of 8-(4-nitro-phenyl)-1,4-dioxa-8-aza-spiro[4.5]decane (13.01 g, 49 mmol) was hydrogenated under 45 psi for one hour using 10% palladium on carbon (2.5 g) as catalyst. The reaction mixture was filtered through celite pad and the filtrate was concentrated down to give a white solid (11.46 g, 100%). This material was taken onto next step immediately. To a stirred mixture, under N2 atmosphere, of the aniline (11.46 g, 49 mmol), butryaldehyde (4.43 mL, 49 mmol) in tetrahydrofuran (250 mL) was added sodium triacetoxyborohydride (14.62 g, 68.6 mmol), and glacial acetic acid (2.82 mL, 49 mmol). The reaction was stirred for two hours. The reaction was quenched with 1 N NaOH (50 mL), diluted with water, extracted with ether 3 times and dried over sodium sulfate. The product was purified by flash silica gel chromatography eluting with 1:1 ethyl acetate/hexanes to give an oil (5.80g, 41%). This material was immediately taken onto next step. A solution of the N-butyl aniline (5.80 g, 19.9 mmol) in a 1:1 mixture of perchloric acid and hydrochloric acid (100 mL) was stirred at room temperature for three days. The reaction mixture was poured onto ice and made basic with concentracted ammonium hydroxide, extracted with ether four times, dried over sodium sulfate and concentrated to give a yellow oil. The yellowish oil was purified by flash silica gel chromatography eluting with 1:1 ethyl acetate/hexanes to give 1-[4-(butylamino)phenyl]-4-piperidinone as an oil (3.84 g, 82%). To a stirred mixture of 1-[4-(butylamino)phenyl]-4-piperidinone (2.46 g, 10 mmol), triethylamine (1.81 mL, 13 mmol), and 4-(dimethylamino)pyridine (DMAP) (catalytic amount) was added ethyl 3-chloro-3-oxopropionate (2.18 g, 13 mmol) dropwise. The reaction was stirred for 18 hours. The reaction mixture was filtered, concentrated in vacuo, taken up in methylene chloride, and washed with saturated sodium bicarbonate two times and dried over sodium sulfate. The product was purified by flash silica gel chromatography eluting with 1:1 ethyl acetate/hexanes to give a yellow oil (3.84 g, 68%); MS (ES) m/z: 361.3(MH+, 100%).

1. additionThe reaction mixture was poured onto ice
2. extractionextracted with ether four times
3. dry with materialdried over sodium sulfate
4. concentrationconcentrated
5. customto give a yellow oil
6. customThe yellowish oil was purified by flash silica gel chromatography
7. washeluting with 1:1 ethyl acetate/hexanes

ORD record

ord-11a60b24671344119da73ef9a0cdf19c

Source dataset

uspto-grants-2006_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07022716B2