4-ETHYLAMINO-PIPERIDINE-1-CARBOXYLIC ACID BENZYL ESTER synthesis

Yield:-

Reaction Conditions:

Stage #1: benzyl 4-oxo-1-piperidinecarboxylate;ethylaminewith sodium tris(acetoxy)borohydride;acetic acid in tetrahydrofuran at 20; for 68 h;
Stage #2: with water;sodium carbonate in tetrahydrofuran;

Steps:

8.a.1

Intermediate 8; N-Ethyl-N-piperidin-4-yl-methane sulfonamide; a) Step 1; 4-Ethylamino-piperidine-1-carboxylic acid benzyl ester; A mixture of 28.93 g (124 mmol) 1-(benzyloxycarbonyl)-4-piperidinone (commercially available, 8.30 g (186 mmol) ethylamine (2N in THF), 39.42 g (186 mmol) sodium triacetoxyborohydride and 11.10 g (186 mmol) acetic acid in 300 mL THF was stirred for 68 h at room temperature. Water and Na₂CO₃ aq. was added and extracted with ethyl acetate. The organic phases were washed with NaCl aq. sat., dried with Na₂SO₄, filtered and evaporated to dryness. The crude title compound was used in the consecutive step. MS(m/e): 263.0 (MH⁺).

References:

US2009/76081,2009,A1 Location in patent:Page/Page column 11-12