ChemicalBook CAS DataBase List 1,2,3,4-Tetrahydroisoquinoline-1,3-dione

1,2,3,4-Tetrahydroisoquinoline-1,3-dione synthesis

14synthesis methods

Product Name:1,2,3,4-Tetrahydroisoquinoline-1,3-dione
CAS Number:4456-77-3
Molecular formula:C9H7NO2
Molecular Weight:161.16

89-51-0

1,2,3,4-Tetrahydroisoquinoline-1,3-dione

4456-77-3

O-carboxyphenylacetic acid (20.0 g, 111 mmol) was mixed with finely ground urea (7.33 g, 122 mmol) and the reaction was heated at 175-185 °C for 2 hours. After completion of the reaction, the mixture was cooled and purified by recrystallization from methanol to give 1,3-[2H,4H]-isoquinolinedione (12.0 g, 67% yield) as a white solid with a melting point of 220-222 °C (literature value 3: 236-238 °C). The structure of the product was confirmed by 1H NMR and 13C NMR: 1H NMR ((CD3)2SO) δ 4.09 (3H, s, CH2), 7.44 (1H, d, J = 7.6 Hz, 5-H), 7.51 (1H, t, J = 7.6 Hz, 7-H), 7.70 (1H, td, J = 7.6, 1.2 Hz, 6-H). 8.07 (1H, dd, J = 7.8, 1.1 Hz, 8-H), 11.36 (1H, s, NH); 13C NMR ((CD3)2SO) (HSQC/HMBC) δ 35.92 (4-C), 124.95 (8a-C), 127.16 (7-C), 127.41 (8-C), 127.87 (5-C) , 133.47 (6-C), 136.66 (4a-C), 165.34 (1-C), 170.99 (3-C).

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Yield: 95%

Reaction Conditions:

with ammonium carbonate

Steps:

7 EXAMPLE 7
EXAMPLE 7 In the following, an illustrative example is given for the preparation of a homophthalimide of general formula (II) from the corresponding homophthalic anhydride of general formula (IV). Homophthalic anhydride (1.62 g, 10 mmol) and ammonium carbonate (1.61 g, 10 mmol) are ground in a mortar and then slowly heated to fusion at about 280° C. After 2 h, the reaction mixture is allowed to cool. The product is practically pure and needs no further treatment. Thus homophthalimide is obtained in 95% yield (153 mg). m.p. 223°-233° C. MS (m/z) 161. NMR δ ppm: 4.02 (s, CH₂ CO), 7.37 (d, J=7.7 Hz, H-5), 7.44 (m, H-7), 7.64 (m, H-6), 8.00 (dd, J=1.3, 7.8 Hz, H-8), 11.29 (bs, NH).

References:

Farmitalia Carlo Erba S.r.L. US5587385, 1996, A

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$18.00/100mg

References