ethyl 1,2,3,4-tetrahydroisoquinoline-3-carboxylate

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 10,10a-Dihydro-5H-imidazo[1,5-b]isoquinoline-1,3-dione was prepared from ethyl 1,2,3,4-tetrahydroisoquinoline-3-carboxylate in analogy to example 23 (yield: 85%) and then 1.48 mmol were reacted as described in example 23 with isocyanatohexane. Yield: 61 mg (12%), M+H+:330.20. 1.48 mmol were reacted

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: This compound can be prepared by condensing 1,2,3,4-tetrahydroisoquinoline-3-carboxylic ethyl ester with N-acetylsarcosine according to the above-described methods; the corresponding acid can be prepared via catalytic hydrogenation of the product ester using Lindlar's catalyst or via base hydrolysis. via base hydrolysis

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a stirred solution of (±)-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid ethyl ester (6.26 g, 30.5 mmol) and 3-phenoxybenzoic acid (7.19 g, 33.6 mmol) in chloroform (150 mL) was added 1-[3-(dimethylamino)propyl]-3-ethylcarbodiimide hydrochloride (6.43 g, 33.5 mmol). The reaction was allowed to proceed overnight and then washed with aqueous sodium bicarbonate solution, dried (sodium sulfate) and concentrated. The crude product was purified by flash chromatography over silica (hexanes/ethyl acetate) to afford 12.07 g (99%) of product as a colorless gum. In chloroform-d solvent, the proton NMR spectra of this compound appears as a 55:45 mixture of rotamers: 1H NMR (CDCl3) δ 7.46-6.90 (m, 13H), 5.46 (t, J=5.6 Hz, 0.55H), 5.18 (d, J=17.6 Hz, 0.45H), 4.80-4.73 (m, 0.45H), 4.68-4.50 (m, 1.55H), 4.22-4.07 (m, 1.10H), 4.05-3.92 (m, 0.90H), 3.34-3.19 (m, 1.55H), 3.16-3.06 (m, 0.45H), 1.19 (t, J=7.1 Hz, 1.65H), 1.04 (t, J=7.1 Hz, 1.35H) ppm. washed with aqueous sodium bicarbonate solution dried (sodium sulfate) concentrated The crude product was purified by flash chromatography over silica (hexanes/ethyl acetate)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 1,2,3,4-Tetrahydroisoquinoline-3-carboxylic acid camphor sulphonic acid salt (Preparation 120, 6 g, 17.2 mmol) was dissolved in ethanol (140 ml) and saturated with hydrogen chloride (gas). The reaction mixture was heated under reflux for 18 h before concentrating in vacuo. The crude residue was dissolved in dichloromethane (150 ml) and washed with sodium hydrogen carbonate (150 ml). The organic layer was collected and washed again with sodium hydrogen carbonate (2×100 ml) before drying (Na2SO4) and concentrating in vacuo to give the title compound as a yellow oil (3.64 g, 100%). The reaction mixture was heated under reflux for 18 h before concentrating in vacuo The crude residue was dissolved in dichloromethane (150 ml) washed with sodium hydrogen carbonate (150 ml) The organic layer was collected washed again with sodium hydrogen carbonate (2×100 ml) before drying (Na2SO4) concentrating in vacuo

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 10,10a-Dihydro-5H-imidazo[1,5-b]isoquinoline-1,3-dione was prepared from ethyl 1,2,3,4-tetrahydroisoquinoline-3-carboxylate in analogy to example 23 (yield: 85%) and then 1.48 mmol were reacted as described in example 23 with isocyanatohexane. Yield: 61 mg (12%), M+H+:330.20. 1.48 mmol were reacted