Pictet-Spengler Tetrahydroisoquinoline Synthesis – a heterocycle formation reaction

In 1911, A. Pictet and T. Spengler condensed phenylethylamine and dimethoxymethane in concentrated hydrochloric acid to give 1,2,3,4-tetrahydroisoquinoline. They also observed a similar reaction when tyrosine and phenylalanine were treated in the same way. Since then, the condensation of a beta-arylethylamine with a carbonyl compound in the presence of a protic or Lewis acid to create a substituted tetrahydroisoquinoline has been known as the Pictet-Spengler tetrahydroisoquinoline synthesis, or the Pictet-Spengler reaction.

A variation of the Pictet-Spengler reaction utilizes an indole as the aromatic substrate. P.D. Bailey accomplished the total synthesis of the alkaloid (-)-suaveoline using this approach.

Total synthesis of the natural product pyranonaphthoquinone was also accomplished utilizing the Pictet-Spengler reaction to generate the precursor naphthopyran intermediate.

Mechanism of the Pictet-Spengler tetrahydroisoquinoline synthesis

Review available Thermo Scientific products for the Pictet-Spengler tetrahydroisoquinoline synthesis:

Catalog # Name Size Price (USD) Qty
A12055.AE Dimethoxymethane, 98% Each
28.65

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31.30
Save 2.65 (8%)
A12055.AP Dimethoxymethane, 98% Each
29.65

Special offer

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Ends: 26-Sep-2025

35.20
Save 5.55 (16%)
A12055.0F Dimethoxymethane, 98% Each
96.65

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107.00
Save 10.35 (10%)
A11141.18 L-Tyrosine, 99% Each
39.65

Online Exclusive

43.40
Save 3.75 (9%)
A11141.22 L-Tyrosine, 99% Each
63.65

Online Exclusive

70.50
Save 6.85 (10%)
A11141.30 L-Tyrosine, 99% Each
104.65

Special offer

Online exclusive

Ends: 26-Sep-2025

123.00
Save 18.35 (15%)
A11141.0B L-Tyrosine, 99% Each
313.65

Special offer

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Ends: 26-Sep-2025

369.00
Save 55.35 (15%)
A10132.14 DL-Phenylalanine, 99% Each
22.65

Online Exclusive

25.10
Save 2.45 (10%)
A10132.22 DL-Phenylalanine, 99% Each
52.65

Special offer

Online exclusive

Ends: 26-Sep-2025

62.00
Save 9.35 (15%)
A10132.36 DL-Phenylalanine, 99% Each
236.65

Online Exclusive

263.00
Save 26.35 (10%)

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