ChemicalBook CAS DataBase List ETHYL 1-BOC-5-OXO-HEXAHYDRO-1H-AZEPINE-4-CARBOXYLATE

ETHYL 1-BOC-5-OXO-HEXAHYDRO-1H-AZEPINE-4-CARBOXYLATE synthesis

4synthesis methods

Product Name:ETHYL 1-BOC-5-OXO-HEXAHYDRO-1H-AZEPINE-4-CARBOXYLATE
CAS Number:141642-82-2
Molecular formula:C14H23NO5
Molecular Weight:285.34

Ethyl 5-oxoazepane-1-carboxylate was prepared by a ring expansion reaction using 4-oxopiperidone hydrochloride and ethyl diazoacetate as starting materials, which was directly used in the next step without purification. The target compound 1-BOC-5-oxoazep

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ETHYL 1-BOC-5-OXO-HEXAHYDRO-1H-AZEPINE-4-CARBOXYLATE

141642-82-2
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$23.00/100mg

Yield: 85%

Reaction Conditions:

with boron trifluoride diethyl etherate in diethyl ether at -5 - 0; for 1 h;Inert atmosphere;

Steps:

5-Oxo-azepane-1,4-dicarboxylic acid 1-tert-butyl ester 4-ethyl ester:
In a dried, N₂-flushed, 500-mL three-necked, round-bottomed flask equipped with a magnetic stir bar, N-BOC-piperidone 1 (20 g, 0.10 mol) and BF3·Et2O (14 mL, 0.11 mol) were diluted in Et₂O (200 mL) then chilled to -5 °C. Slowly, ethyl diazoacetate (13.7 mL, 0.13 mol) was added over a period of 1 h causing extreme gas evolution. The internal temperature was maintained between -5 °C and 0 °C during the addition. The reaction was stirred for 1 h at 0 °C then slowly quenched with 30% Na₂CO₃ at 0 °C. The pH was adjusted to 7-8 and then H₂O (30 mL) was added to the mixture. The organic layer was extracted with EtOAc (2 x 75 mL), dried with Na₂SO₄, filtered, and concentrated to orange oil. The crude oil was purified by column chromatography (silica gel column: 14 cm OD, 8 cm in height and eluting with 9/1 hexanes/EtOAc increasing to 7/3 hexanes/EtOAc) to provide a light yellow oil in 85% yield. MS (electrospray): C₁₄H₂₃NO₅; m/z not found. ¹H NMR (400 MHz, CDCl3): δ 4.25 - 2.03 (m, 11 H), 1.47 - 1.45 (d, J = 7.8 Hz, 9 H), 1.31 - 1.24 (m, 3 H).

References:

Dvorak, Curt A.;Rudolph, Dale A.;Nepomuceno, Diane;Dvorak, Lisa;Lord, Brian;Fraser, Ian;Bonaventure, Pascal;Lovenberg, Timothy;Carruthers, Nicholas I. [Bioorganic and Medicinal Chemistry Letters,2021,vol. 31,art. no. 127669] Location in patent:supporting information

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79099-07-3 Synthesis