EXPERIMENTAL
The IR spectra were taken on a UR-20 spectrometer for suspensions in vaseline oil. The 1H NMR spec-
tra were taken on a Varian Mercury 300VX spectrometer at 300 MHz in DMSO-d6 with TMS as internal
standard. The mass spectra were obtained on an MKh-1321A mass spectrometer with direct sample inlet into the
ion source and 70 eV ionizing electron energy. The purity of the compounds was monitored by thin-layer
chromatography on Silufol UV-254 plates using eluents: pyridine–butanol, 1:3 (for compounds 1, 3b, and 5), or
pyridine–butanol, 1:1 (for compound 6). The Rf values obtained under these conditions are given in Table 1.
3-Amino-7,7-dimethyl-7,8-dihydro-5H-pyrano[4,3-b]thieno[3,2-e]pyridine-2-carboxylic acid (1). A
mixture of ethyl ester of acid 1 (3.1 g, 0.01 mol) and 5% aqueous sodium hydroxide (50 ml) was heated at reflux
for 4 h. After cooling, the reaction mixture was brought to pH 6 by adding acetic acid. The crystalline precipitate
of acid 1 was filtered off, washed with water and ethanol, dried, and recrystallized from ethanol. The IR spectral
1
data corresponded to our previous results [4]. H NMR spectrum, , ppm: 1.30 (6H, s, 7-(CH3)2); 2.87 (2H, s,
8-CH2); 4.82 (2H, s, 5-CH2); 6.95 (2H, br. s, NH2); 8.11 (1H, s, 4-CH); 12.00 (1H, br. s, CO2H).
2,8,8-Trimethyl-7,10-dihydro-4H,8H-pyrano[3",4":5',6']pyrido[3',2':4,5]thieno[3,2-d][1,3]oxazin-
4-one (3a) was prepared as described in our previous work [4] by heating acid 1 with acetic anhydride at reflux
for 1 h. After cooling the reaction mixture, the crystalline precipitate of oxazinone 3a was filtered off, washed
with water and ether, dried, and recrystallized from ethanol to give compound 3a in 74% yield; mp 243–244°C
(mp 242–243°C [4]).
8,8-Dimethyl-2-propyl-7,10-dihydro-4H,8H-pyrano[3",4":5',6']pyrido[3',2':4,5]thieno[3,2-d][1,3]-
oxazin-4-one (3b) was obtained analogously to compound 3a by heating a mixture of acid 1 (2.8 g, 0.01 mol)
and butyric anhydride (20 ml) at reflux and subsequent work-up. IR spectrum, , cm–1: 1560, 1590, 1620 (C=C,
1
C=N), 1750 (C=O lactone). H NMR spectrum, , ppm (J, Hz): 1.12 (3H, t, J = 7.5, CH2CH2CH3); 1.33 (6H, s,
8-(CH3)2); 1.94 (2H, m, CH2CH3); 2.79 (2H, t, J = 7.4, CH2CH2CH3); 2.99 (2H, s, 7-CH2); 4.91 (2H, s, 10-CH2);
8.20 (1H, s, 11-CH).
3-Alkyl-2,8,8-trimethyl-7,10-dihydro-8H-pyrano[3",4":5',6']pyrido[3',2':4,5]thieno[3,2-d]pyrimi-
din-4(3H)-ones (5a–e) and 3-Alkyl-8,8-dimethyl-2-propyl-7,10-dihydro-8H-pyrano[3",4":5',6']pyri-
do[3',2':4,5]thieno[3,2-d]pyrimidin-4(3H)-ones (5f–j), 3-Acetylamino-N-alkyl-7,7-dimethyl-7,8-dihydro-
5H-pyrano[4,3-b]thieno[3,2-e]pyridine-2-carboxamides (6a–c), and N-Alkyl-3-butanoylamino-7,7-di-
methyl-7,8-dihydro-5H-pyrano[4,3-b]thieno[3,2-e]pyridine-2-carboxamides (6d–f) (General Method).
A mixture of compound 3 (0.01 mol) and amine 4 (0.01 mol) in dioxane (30 ml) and water (5 ml) was heated at
reflux for 3 h. The reaction mixture was cooled and the solvents evaporated off. Water was added to the residue.
The crystalline precipitate of compounds 5 or 6 was filtered off, washed with water and ether, dried, and
recrystallized from ethanol. The IR spectra of products 5a–j contain characteristic stretching and deformation
bands at 1550, 1600, 1620 (C=C, C=N), 1680 cm–1 (C=O). The IR spectra of products 6a–f have characteristic
bands at 1560, 1590, 1600 (C=C), 1650, 1660 (C=O), 3340, 3350 cm–1 (NH).
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A. G. Akopyan, Khim.-Farm. Zh., 32, No. 9, 15 (1998).
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