SYNTHESIS OF NEW DI-, TETRA-, AND HEXAHYDROPYRAZOLO[3,4-e][1,4]DIAZEPINE
1001
7.39 d (2H, Harom, J = 8.3 Hz), 7.40 s (1H, 3-H).
13C NMR spectrum, δC, ppm: 34.80 (NCH3), 45.81
(CH2), 57.17 (CH), 99.09 (C3a), 128.14 and 128.37
(C2′, C3′), 131.52 (C4′), 139.61 (C3), 140.65 (C1′),
145.53 (C8a), 165.45 (C=O). Found, %: C 56.17;
H 4.70; N 20.07. m/z 277 [M + 1]+. C13H13ClN4O. Cal-
culated, %: C 56.43; H 4.74; N 20.25. M 276.73.
Yield 60% (a), mp 135–136°C. IR spectrum, ν, cm–1:
1
3370–3225 (NH), 1605 (C=O). H NMR spectrum, δ,
ppm: 3.38–3.49 m (1H, CH), 3.60–3.69 m (1H, CH),
4.71–4.79 m (1H, CH), 7.09–7.32 m (6H, Harom, NH),
7.38–7.45 m (1H, Harom), 7.49–7.61 m (4H, Harom),
13
7.68 s (1H, 3-H). C NMR spectrum, δC, ppm: 45.53
(CH2), 57.20 (C7), 99.66 (C3a), 114.96 d (C3″, JCF
=
21.4 Hz), 124.36 (C2′), 127.55 (C4′), 128.27 d (C2″,
7-(4-Methoxyphenyl)-1-methyl-5,6,7,8-tetrahy-
dropyrazolo[3,4-e][1,4]diazepin-4(1H)-one (XIVf).
Yield 72% (a), mp 217–218°C. IR spectrum, ν, cm–1:
JCF = 8.0 Hz), 129.41 (C3′), 137.67 d (C1″, JCF
=
2.5 Hz), 138.26 (C1′) 142.00 (C3), 145.36 (C8a),
161.15 d (C4″, JCF = 242.3 Hz), 165.36 (C=O). Found,
%: C 67.33; H 4.80; N 17.12. m/z 323 [M + 1]+.
C18H15FN4O. Calculated, %: C 67.07; H 4.69; N 17.38.
M 322.34.
1
3390–3285 (NH), 1615 (C=O). H NMR spectrum, δ,
ppm: 3.25–3.35 m (1H, CH), 3.45–3.56 m (1H, CH),
3.57 s (3H, NCH3), 3.73 s (3H, OCH3), 4.59–4.65 m
(1H, CH), 6.90 d (2H, Harom, J = 8.6 Hz), 7.03 s (1H,
NH), 7.10 s (1H, NH), 7.20 d (2H, Harom, J = 8.6 Hz),
1-Substituted 1,4,5,6,7,8-hexahydropyrazolo-
[3,4-e][1,4]diazepines XVa–XVd (general procedure).
Lithium tetrahydridoaluminate, 3.78 g (100 mmol),
was dispersed in 150 ml of tetrahydrofuran, 10.86 g
(100 mmol) of chloro(trimethyl)silane was added
under stirring in an argon atmosphere, and 20 mmol of
compound Xa–Xc (a) or XIVa–XIVc or XIVg (b) was
then added in portions. The mixture was heated for 40–
45 h under reflux, treated in succession with 15 ml of
propan-2-ol, 10 ml of 20% aqueous sodium hydroxide,
and 10 ml of 40% aqueous ammonia, the inorganic
material was filtered off, and the filtrate was evaporat-
ed. In the reactions with Xb, XIVb, and XIVg, the
residue was dissolved in 20 ml of ethanol, the solution
was acidified to pH 3–4 with concentrated hydro-
chloric acid, the mixture was evaporated under reduced
pressure (water-jet pump), and the solid residue was
recrystallized from propan-2-ol.
1-Methyl-1,4,5,6,7,8-hexahydropyrazolo[3,4-e]-
[1,4]diazepine (XVa). Oily substance. Yield 48% (a),
53% (b). IR spectrum: ν 3340–3250 cm–1 (NH).
1H NMR spectrum, δ, ppm: 2.78–2.85 m (2H, CH2),
2.91–2.99 m (2H, CH2), 3.40–3.54 m (2H, CH2), 3.52 s
(3H, CH3), 5.53 br.s (1H, NH), 6.90 s (1H, 3-H).
13C NMR spectrum, δC, ppm: 34.54 (CH3), 45.09
(CH2), 49.11 (CH2), 52.75 (CH2), 107.16 (C3a), 135.34
(C3), 146.97 (C8a). Found, %: C 55.38; H 8.06;
N 36.58. m/z 153 [M + 1]+. C7H12N4. Calculated, %:
C 55.24; H 7.95; N 36.81. M 152.20.
13
7.41 s (1H, 3-H). C NMR spectrum, δC, ppm: 34.79
(NCH3), 46.57 (CH2), 55.06 (OCH3), 57.62 (CH),
99.09 (C3a), 113.68 (C3′), 127.59 (C2′), 133.64 (C1′),
139.61 (C3), 145.76 (C8a), 158.38 (C4′), 165.45 (C=O).
Found, %: C 61.51; H 6.05; N 20.18. m/z 273 [M + 1]+.
C14H16N4O2. Calculated, %: C 61.75; H 5.92; N 20.57.
M 272.31.
1-Benzyl-7-phenyl-5,6,7,8-tetrahydropyrazolo-
[3,4-e][1,4]diazepin-4(1H)-one (XIVg). Yield 72%
(a), mp 198–200°C. IR spectrum, ν, cm–1: 3350–3200
1
(NH), 1635 (C=O). H NMR spectrum, δ, ppm: 3.32–
3.44 m (1H, CH), 3.47–3.62 m (1H, CH), 4.65–4.78 m
(1H, CH), 5.15–5.32 m (2H, CH2), 7.01–7.43 m (12H,
Harom, NH), 7.51 s (1H, 3-H). 13C NMR spectrum, δC,
ppm: 46.06 (CH2), 50.35 (CH2), 57.60 (CH), 99.10
(C3a); 126.42, 126.90, 127.06, 128.23, 128.38, 129.42,
137.34, 140.67 (Carom); 141.52 (C3), 145.87 (C8a),
165.64 (C=O). Found, %: C 71.75; H 5.60; N 17.38.
m/z 319 [M + 1]+. C19H18N4O. Calculated, %: C 71.68;
H 5.70; N 17.60. M 318.38.
1,7-Diphenyl-5,6,7,8-tetrahydropyrazolo[3,4-e]-
[1,4]diazepin-4(1H)-one (XIVh). Yield 51% (a),
mp 131–132°C. IR spectrum, ν, cm–1: 3380–3220
1
(NH), 1610 (C=O). H NMR spectrum, δ, ppm: 3.40–
3.49 m (1H, CH), 3.60–3.71 m (1H, CH ), 4.69–4.78 m
(1H, CH), 7.12 s (1H, NH), 7.20–7.29 m (4H, Harom
,
NH), 7.30–7.37 m (2H, Harom), 7.38–7.44 m (1H,
H
arom), 7.49–7.61 m (4H, Harom), 7.68 s (1H, 3-H).
13C NMR spectrum, δC, ppm: 45.68 (CH2), 57.86
(CHPh), 99.65 (C3a); 124.61, 126.29, 126.80, 127.50,
128.23, 129.39, 138.29, 141.52 (Carom); 142.00 (C3),
145.51 (C8a), 165.33 (C=O). Found, %: C 70.83;
H 5.11; N 18.62. m/z 305 [M + 1]+. C18H16N4O. Cal-
culated, %: C 71.04; H 5.30; N 18.41. M 304.35.
1-Benzyl-1,4,5,6,7,8-hexahydropyrazolo[3,4-e]-
[1,4]diazepine dihydrochloride (XVb). Yield 45%
(a), 48% (b); mp 138–139°C. IR spectrum: ν 3370–
1
3260 cm–1 (NH). H NMR spectrum, δ, ppm: 3.21–
3.39 m (4H, CH2), 3.95–4.09 m (2H, CH2), 5.27 s (2H,
CH2), 6.30 br.s (1H, NH), 7.13–7.24 m (2H, Harom),
7.24–7.38 m (3H, Harom), 7.42 s (1H, 3-H), 9.34 br.s
7-(4-Fluorophenyl)-1-phenyl-5,6,7,8-tetrahydro-
pyrazolo[3,4-e][1,4]diazepin-4(1H)-one (XIVi).
+
(2H, NH2 ). 13C NMR spectrum, δC, ppm: 41.67 (CH2),
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 48 No. 7 2012