Hydrochloric Acid → 2-chloro-7-ethyl-6,7,8,9-tetrahydro-5H-pyrazino[2,3-d]azepine

HRID 330883Notes

Reaction equation

[CH2:1]([N:3]1[CH2:9][CH2:8][C:7]2[N:10]=[CH:11][C:12](N)=[N:13][C:6]=2[CH2:5][CH2:4]1)[CH3:2].N([O-])=O.[Na+].[ClH:19]>O.[Cu]Br>[Cl:19][C:12]1[CH:11]=[N:10][C:7]2[CH2:8][CH2:9][N:3]([CH2:1][CH3:2])[CH2:4][CH2:5][C:6]=2[N:13]=1

Participants

Conditions

Temperature: -5 °C

Procedure

26.5 g of 7-ethyl-6,7,8,9-tetrahydro-5H-pyrazino[2,3-d]azepin-2-ylamine (U.S. Pat. No. 4,409,220) are suspended in 130 ml conc. hydrochloric acid, mixed with 0.1 g copper(I)bromide and cooled to −5° C. A suspension of 11 g sodium nitrite in 14 ml of water is slowly added dropwise. The reaction mixture is stirred for 15 hours at ambient temperature and evaporated almost to dryness. The residue is slowly added to ice water and potassium carbonate. The product is extracted with dichloromethane and precipitated as the hydrochloride with an ethereal HCl solution. 14.3 g product are obtained. M.p=258-262° C.

Workup

additionis slowly added dropwise
customevaporated almost to dryness
additionThe residue is slowly added to ice water and potassium carbonate
extractionThe product is extracted with dichloromethane
customprecipitated as the hydrochloride with an ethereal HCl solution

Sources & evidence

ORD record: ord-1ca3b1cf3815411a901250028df8d9ae
Source dataset: uspto-grants-2014_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08877758B2

Reaction notes

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