Hydrochloric Acid → 1-Methyl-4-(2,4,6-trimethoxyphenyl)-1,2,3,6-tetrahydropyridine

HRID 340760Notes

Reaction equation

[CH3:1][N:2]1[CH2:7][CH2:6][C:5](=O)[CH2:4][CH2:3]1.[CH3:9][O:10][C:11]1[CH:16]=[C:15]([O:17][CH3:18])[CH:14]=[C:13]([O:19][CH3:20])[CH:12]=1.Cl>C(O)(=O)C>[CH3:1][N:2]1[CH2:7][CH:6]=[C:5]([C:12]2[C:13]([O:19][CH3:20])=[CH:14][C:15]([O:17][CH3:18])=[CH:16][C:11]=2[O:10][CH3:9])[CH2:4][CH2:3]1

Participants

Conditions

Temperature: 87.5 °C

Procedure

1-methyl-4-piperidone (340 g, 3.0 mol) was added slowly, to a solution of 1,3,5-trimethoxybenzene (500 g, 2.97 mol) in glacial acetic acid (600 mL), maintaining the temperature of the reaction mixture below 40° C. Conc. HCl (450 mL) was added over 20 min. The temperature was raised to 85-90° C. and the reaction mixture was stirred for 3.5 h. It was allowed to cool to 40° C., poured over crushed ice (4 kg) and stirred for 20 min. The precipitate of unreacted 1,3,5-trimethoxybenzene was filtered off. The filtrate was basified, below 10° C., to pH 11-12 using a 50% aqueous NaOH solution. The off white solid obtained was filtered, washed with water and dried to obtain the compound, 1-methyl-4-(2,4,6-trimethoxy-phenyl)-1,2,3,6-tetrahydropyridine.

Workup

temperaturemaintaining the temperature of the reaction mixture below 40° C
temperatureto cool to 40° C.
additionpoured
stirringstirred for 20 min
filtrationThe precipitate of unreacted 1,3,5-trimethoxybenzene was filtered off
customwas basified, below 10° C., to pH 11-12
customThe off white solid obtained
filtrationwas filtered
washwashed with water
customdried

Sources & evidence

ORD record: ord-489612efa9b34af1b65bea80da484394
Source dataset: uspto-grants-2014_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08895605B2

Reaction notes

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