7ꢀArylpyrano[4,3ꢀd]pyrimidinium salts
Russ.Chem.Bull., Int.Ed., Vol. 61, No. 3, March, 2012
629
1,3ꢀDimethylꢀ2,4ꢀdioxoꢀ1,2,3,4ꢀtetrahydropyrido[4,3ꢀd]ꢀ
pyrimidinium bromides 12a—f (general procedure). A mixture
of salt 4 (0.5 mmol), AcOH (2 mL), and aromatic amine
(0.525 mmol) was refluxed for 15 min. The resulting solution
was concentrated. The residue was triturated with diethyl ether,
filtered, washed with diethyl ether, and dried at 100 C.
1,3ꢀDimethylꢀ6,7ꢀdiphenylꢀ2,4ꢀdioxoꢀ1,2,3,4ꢀtetrahydroꢀ
pyrido[4,3ꢀd]pyrimidinium bromide (12a). The yield was 203 mg
(96%), colorless crystals, which undergo decomposition at temꢀ
peratures above 149 C (diethyl ether). Found (%): C, 59.38;
H, 4.35; Br, 18.97. C21H18BrN3O2. Calculated (%): C, 59.45;
H, 4.28; Br, 18.83. 1H NMR (CDCl3), : 3.43 and 3.82 (both s,
3 H each, N(3)Me, N(1)Me); 7.25—7.46 (m, 6 H, ArH(3), ArH(4),
ArH(5), Ar´H(3), Ar´H(4), Ar´H(5)); 7.56—7.67 (m, 4 H,
ArH(2), ArH(6), Ar´H(2), Ar´H(6)); 7.74 and 9.11 (both s,
1 H each, H(8), H(5)). IR, /cm–1: 1638, 1669 (C=O).
6ꢀ(4ꢀBromophenyl)ꢀ1,3ꢀdimethylꢀ2,4ꢀdioxoꢀ7ꢀphenylꢀ1,2,3,4ꢀ
tetrahydropyrido[4,3ꢀd]pyrimidinium bromide (12b). The yield
was 240 mg (95%), colorless crystals, which undergo decompoꢀ
sition at temperatures above 167 C (diethyl ether). Found (%):
C, 50.21; H, 3.48; Br, 32.04. C21H17Br2N3O2. Calculated (%):
C, 50.13; H, 3.41; Br, 31.76. 1H NMR (CDCl3), : 3.42 and 3.79
(both s, 3 H each, N(3)Me, N(1)Me); 7.27—7.52 (m, 5 H,
ArH(3), ArH(4), ArH(5), Ar´H(3), Ar´H(5)); 7.54—7.66 (m, 4 H,
ArH(2), ArH(6), Ar´H(2), Ar´H(6)); 7.67 and 9.09 (both s,
1 H each, H(8), H(5)). IR, /cm–1: 1637, 1673 (C=O).
7ꢀ(4ꢀMethoxyphenyl)ꢀ1,3ꢀdimethylꢀ2,4ꢀdioxoꢀ6ꢀphenylꢀ
1,2,3,4ꢀtetrahydropyrido[4,3ꢀd]pyrimidinium bromide (12c). The
yield was 182 mg (80%), yellow crystals, which undergo deꢀ
composition at temperatures above 149 C (diethyl ether).
Found (%): C, 57.98; H, 4.51; Br, 17.68. C22H20BrN3O3. Calꢀ
culated (%): C, 58.16; H, 4.44; Br, 17.59. 1H NMR (CDCl3), :
3.42 and 3.74 (both s, 3 H each, N(3)Me, N(1)Me); 3.83 (s, 3 H,
OMe); 6.77 and 7.53 (both d, 2 H each, ArH(3), ArH(5), ArH(2),
ArH(6), J = 8.5 Hz); 7.32—7.48 (m, 3 H, Ar´H(3), Ar´H(4),
Ar´H(5)); 7.56—7.67 (m, 2 H, Ar´H(2), Ar´H(6)); 7.75 and 9.06
(both s, 1 H each, H(8), H(5)). IR, /cm–1: 1637, 1675 (C=O).
6ꢀ(4ꢀBromophenyl)ꢀ7ꢀ(4ꢀmethoxyphenyl)ꢀ1,3ꢀdimethylꢀ2,4ꢀ
dioxoꢀ1,2,3,4ꢀtetrahydropyrido[4,3ꢀd]pyrimidinium bromide (12d).
The yield was 244 mg (91%), pale yellow crystals, which underꢀ
go decomposition at temperatures above 151 C (diethyl ether).
Found (%): C, 49.65; H, 3.63; Br, 29.78. C22H19Br2N3O3. Calꢀ
culated (%): C, 49.56; H, 3.59; Br, 29.97. 1H NMR (CDCl3), :
3.41 (s, 3 H, N(3)Me); 3.77 and 3.79 (both s, 6 H each, N(1)Me,
OMe); 6.80 and 7.60 (both d, 2 H each, ArH(3), ArH(5), ArH(2),
ArH(6), J = 8.8 Hz); 7.50 and 7.51 (both d, 2 H each, Ar´,
J = 8.7 Hz); 7.67 and 9.05 (both s, 1 H each, H(8), H(5)). IR,
/cm–1: 1636, 1675 (C=O).
was 270 mg (93%), colorless crystals, which undergo decompoꢀ
sition at temperatures above 189 C (diethyl ether). Found (%):
C, 43.49; H, 2.71; Br, 41.29. C21H16Br3N3O2. Calculated (%):
C, 43.33; H, 2.77; Br, 41.18. 1H NMR (CDCl3), : 3.45 and 3.80
(both s, 3 H each, N(3)Me, N(1)Me); 7.43—7.58 (m, 6 H,
Ar´H(3), Ar´H(5), Ar); 7.64 (d, 2 H, Ar´H(2), Ar´H(6), J = 8.5 Hz);
7.69 and 9.08 (both s, 1 H each, H(8), H(5)). IR, /cm–1: 1637,
1674 (C=O).
6ꢀAminoꢀ7ꢀarylꢀ1,3ꢀdimethylꢀ2,4ꢀdioxoꢀ1,2,3,4ꢀtetrahydroꢀ
pyrido[4,3ꢀd]pyrimidinium bromides 15a—c (general procedure).
A mixture of salt 4 (0.5 mmol), AcOH (2 mL), and hydrazine
hydrate (0.028 mL, 0.55 mmol) was refluxed for 5 min. The
resulting solution was concentrated. The residue was recrystalꢀ
lized from EtOH, filtered off, washed with EtOH and CHCl3,
and dried at 100 C.
6ꢀAminoꢀ1,3ꢀdimethylꢀ2,4ꢀdioxoꢀ7ꢀphenylꢀ1,2,3,4ꢀtetrahyꢀ
dropyrido[4,3ꢀd]pyrimidinium bromide (15a). The yield was 144 mg
(79%), colorless crystals, which undergo decomposition at temꢀ
peratures above 194 C (EtOH). Found (%): C, 49.55; H, 4.23;
Br, 21.77. C15H15BrN4O2. Calculated (%): C, 49.60; H, 4.16;
Br, 22.00. 1H NMR (DMSOꢀd6), : 3.35 and 3.63 (both s,
3 H each, N(3)Me, N(1)Me); 7.58—7.73, 7.66 (m + s, 5 H,
ArH(3), ArH(4), ArH(5), NH2); 7.78—7.89 (m, 2 H, ArH(2),
ArH(6)); 7.95 and 9.46 (both s, 1 H each, H(8), H(5)). IR,
/cm–1: 1630, 1672 (C=O); 3022, 3117 br (NH2).
6ꢀAminoꢀ7ꢀ(4ꢀmethoxyphenyl)ꢀ1,3ꢀdimethylꢀ2,4ꢀdioxoꢀ
1,2,3,4ꢀtetrahydropyrido[4,3ꢀd]pyrimidinium bromide (15b). The
yield was 151 mg (77%), colorless crystals, which undergo deꢀ
composition at temperatures above 194 C (EtOH). Found (%):
C, 48.72; H, 4.40; Br, 20.49. C16H17BrN4O3. Calculated (%):
C, 48.87; H, 4.36; Br, 20.32. 1H NMR (DMSOꢀd6), : 3.34 and
3.63 (both s, 3 H each, N(3)Me, N(1)Me); 3.88 (s, 3 H, OMe);
7.19 and 7.84 (both d, 2 H each, ArH(3), ArH(5), ArH(2),
ArH(6), J = 8.9 Hz); 7.64 (s, 2 H, NH2); 7.87 and 9.41 (both s,
1 H each, H(8), H(5)). IR, /cm–1: 1630, 1677 (C=O); 3009,
3075 br (NH2).
6ꢀAminoꢀ7ꢀ(4ꢀbromophenyl)ꢀ1,3ꢀdimethylꢀ2,4ꢀdioxoꢀ1,2,3,4ꢀ
tetrahydropyrido[4,3ꢀd]pyrimidinium bromide (15c). The yield
was 164 mg (74%), colorless crystals, which undergo decomposiꢀ
tion at temperatures above 195 C (EtOH). Found (%): C, 40.93;
H, 3.25; Br, 36.01. C15H14Br2N4O2. Calculated (%): C, 40.75;
H, 3.19; Br, 36.15. 1H NMR (DMSOꢀd6), : 3.34 and 3.62 (both s,
3 H each, N(3)Me, N(1)Me); 7.64 (s, 2 H, NH2); 7.78 and 7.87
(both d, 2 H each, ArH(3), ArH(5), ArH(2), ArH(6), J = 8.4 Hz);
7.98 and 9.45 (both s, 1 H each, H(8), H(5)). IR, /cm–1: 1628,
1655 (C=O); 3017, 3079 br (NH2).
1,3ꢀDimethylꢀ5ꢀnitromethylꢀ7ꢀphenylꢀ1,5ꢀdihydroꢀ2Hꢀ
pyrano[4,3ꢀd]pyrimidineꢀ2,4(3H)ꢀdione (16). Triethylamine
(0.14 mL, 1 mmol) was added dropwise to a mixture of salt 4a
(175 mg, 0.5 mmol) and nitromethane (2 mL). The reaction
mixture was heated to boiling and then cooled. The precipitate
of the byꢀproduct of the reaction with water was filtered off and
discarded. The filtrate was concentrated. The residue was disꢀ
solved in chloroform, washed three times with water, and conꢀ
centrated. The precipitate was recrystallized from EtOH and
dried at 100 C. The yield was 55 mg (33%), yellow crystals, m.p.
171—173 C (EtOH). Found (%): C, 58.19; H, 4.70. C16H15N3O5.
Calculated (%): C, 58.36; H, 4.59. 1H NMR (CDCl3), : 3.36
and 3.53 (both s, 3 H each, N(1)Me, N(3)Me); 4.46—4.88
(dd + dd, 2 H, CH2, AB part of the ABX system, J = 2.6 Hz,
J = 10.0 Hz, J = 12.5 Hz); 6.17 (s, 1 H, H(8)); 6.35 (dd, 1 H,
7ꢀ(4ꢀBromophenyl)ꢀ1,3ꢀdimethylꢀ2,4ꢀdioxoꢀ6ꢀphenylꢀ
1,2,3,4ꢀtetrahydropyrido[4,3ꢀd]pyrimidinium bromide (12e). The
yield was 243 mg (97%), colorless crystals, which undergo
decomposition at temperatures above 151 C (diethyl ether).
Found (%): C, 50.03; H, 3.48; Br, 32.01. C21H17Br2N3O2. Calꢀ
culated (%): C, 50.13; H, 3.41; Br, 31.76. 1H NMR (CDCl3), :
3.45 and 3.83 (both s, 3 H each, N(3)Me, N(1)Me); 7.36—7.49
(m, 5 H, Ar´H(3), Ar´H(4), Ar´H(5), ArH(3), ArH(5)); 7.54
(d, 2 H, ArH(2), ArH(6), J = 8.9 Hz); 7.60—7.67 (m, 2 H,
Ar´H(2), Ar´H(6)); 7.77 and 9.11 (both s, 1 H each, H(8), H(5)).
IR, /cm–1: 1636, 1673 (C=O).
6,7ꢀBis(4ꢀbromophenyl)ꢀ1,3ꢀdimethylꢀ2,4ꢀdioxoꢀ1,2,3,4ꢀ
tetrahydropyrido[4,3ꢀd]pyrimidinium bromide (12f). The yield