1,2,3,4-Tetrahydroisoquinoline → Racemic 4-benzothiazol-6-yl-2-methyl-1,2,3,4-tetrahydroisoquinoline

HRID 402134Notes

Reaction equation

HRID 402134 reaction equation
Br[C:2]1[CH:10]=[CH:9][C:5]2[N:6]=[CH:7][S:8][C:4]=2[CH:3]=1.[CH2:11]1[C:20]2[C:15](=[CH:16][CH:17]=[CH:18][CH:19]=2)[CH2:14][CH2:13][NH:12]1.[C:21]([OH:28])(=[O:27])/[CH:22]=[CH:23]\[C:24]([OH:26])=[O:25]>CO>[S:8]1[C:4]2[CH:3]=[C:2]([CH:14]3[C:15]4[C:20](=[CH:19][CH:18]=[CH:17][CH:16]=4)[CH2:11][N:12]([CH3:21])[CH2:13]3)[CH:10]=[CH:9][C:5]=2[N:6]=[CH:7]1.[C:21]([OH:28])(=[O:27])/[CH:22]=[CH:23]\[C:24]([OH:26])=[O:25].[S:8]1[C:4]2[CH:3]=[C:2]([CH:14]3[C:15]4[C:20](=[CH:19][CH:18]=[CH:17][CH:16]=4)[CH2:11][N:12]([CH3:21])[CH2:13]3)[CH:10]=[CH:9][C:5]=2[N:6]=[CH:7]1

Participants

6

Reactant 3

HCID 70461,2,3,4-TetrahydroisoquinolineHCID 444266Maleic AcidHCID 27951716-Bromo-1,3-benzothiazole

Product 2

HCID 11587242Racemic 4-benzothiazol-6-yl-2-methyl-1,2,3,4-tetrahydroisoquinolineHCID 131727471(+/-)4-Benzothiazol-6-yl-2-methyl-1,2,3,4-tetrahydroisoquinoline, maleate salt

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent2×

Procedure

Racemic 4-benzothiazol-6-yl-2-methyl-1,2,3,4-tetrahydroisoquinoline was prepared from 6-bromo-benzothiazole by a method similar to the one described in Example 129 (Steps B to C). The desired tetrahydroisoquinoline (20.5 mg) was dissolved in methanol and treated with a solution of maleic acid in methanol (1 mL) at 0° C. The solution was stirred at room temperature overnight, then concentrated, and the solid was washed with diethyl ether providing (+/−)-4-benzothiazol-6-yl-2-methyl-1,2,3,4-tetrahydroisoquinoline, maleate salt (30 mg, 98%, >99% AUC HPLC): 1H NMR (CD3OD, 500 MHz) δ 9.28 (d, J=3.9 Hz, 1H), 8.09-8.08 (m, 1H), 8.00-7.99 (m, 1H), 7.44-7.42 (m, 1H), 7.36-7.25 (m, 3H), 6.93-6.92 (m, 1H), 6.26-6.25 (s, 2H), 4.80-4.78 (m, 1H), 4.64-4.56 (m, 2H), 3.93-3.89 (m, 1H), 3.63-3.61 (m, 1H), 3.08 (s, 3H); ESI-MS m/z=281 [M+H]+.

Workup

  1. concentrationconcentrated
  2. washthe solid was washed with diethyl ether

Sources & evidence

ORD record
ord-cefecca30d1446918dd766d0a941efc8
Source dataset
uspto-grants-2014_06
Patent number
US08741901B2

Reaction notes

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