1585
S. Siddiqui et al. ■Some New Derivatives of Harmaline Series of Bases
1620 (aromatic C =C ), 1340 and 1152 cm
1
2-Acetyl-7-benzamido-3-(2-benzamidoethyl)-
(0 = S = 0 ). UV (MeOH) Amax: 215, 265 and 325 nm;
Amin: 242 and 296 nm; (MeOH —HC1) Amax: 215, 267
and 361 nm; Amin: 245 and 302 nm; (M eO H -N aO H )
Amax: 210, 265 and 325 nm; Amin: 242 and 295 nm.
Mass: M^ = 383.13039 (calcd. for C2(lH21N30 3S =
383.13033). Other diagnostic fragments at m/e 368,
242 (B .P.), 141 and 77.
6-methoxyindole (5)
2
ml of freshly distilled benzoyl chloride was grad-
ually added with constant shaking to a suspension of
8-aminoharmaline hydrochloride (0.5 g) in 10%
aqueous sodium hydroxide solution. The reaction
mixture was kept at room temperature for about
45 min, and worked up in the usual manner yielding
5; m.p. 210—211 °C (colourless rods from acetone).
IR (KBr) vmax: 3400 (indolic NH), 3360, 3280 (amide
NH), 1650, 1660 (C = 0 ) and 1625 cm-1 (aromatic
C =C ). UV (MeOH) Amax: 205, 225, 252 and 330 nm;
Amin: 216, 245 and 285 nm. Mass: M+ = 455.18431
(calcd. for C27H25N304 = 455.18447). Other diagnos-
tic fragments at mte 412, 334, 321, 105 (B.P.) and 77.
‘H NMR (Table I).
2-Acetyl-7-benzenesulfonamido-
3-(2-benzenesulfonamidoethyl)-6-methoxyindole (8)
A
solution of 8-aminoharmaline hydrochloride
(0.5 g) in pyridine (1 ml) was kept with benzenesul-
fonyl chloride (2 ml) at room temperature overnight.
The ethyl acetate layer obtained on usual workup of
the reaction mixture was shaken out with dilute
aqueous alkali. The alkaline extract on acidification
afforded 8 as light yellow crystallizate which formed
fine needles from ethyl acetate-methanol (9:1), m.p.
100-101 °C (yield 74%). IR (KBr) vmax: 3400, 3240,
3160 (NH ), 1640 (C = 0 ). Mass: M+ = 527.29401
(calcd. for C2.H 2,N 30 6S2 = 527.29429). *H NMR
(Table I).
8-Benzenesulfonamido-3,4-dihydro-7-methoxy-
1-methyl-ß-carboline (6)
A solution of 8-aminoharmaline (0.5 g) in pyridine
(3 ml) was kept at room temperature overnight with
0.3 ml of benzenesulfonyl chloride. On usual work-
ing, 6 was obtained as a yellowish crystallizate, which
formed yellow rods on repeated crystallizations from
hot water, m.p. 238—240 °C (yield 74%). IR (KBr)
vmax: 3400 (indolic NH ), 3240 (N H -S O ,-), 1625
(aromatic C =C ), 1340 and 1165 cm-1 ( 0 = S= 0 ).
UV (MeOH) Amax: 215, 265 and 357 nm; Amin: 242
and 298 nm; (MeOH —HC1) Amax: 215, 267 and
361 nm; Amin: 245 and 302 nm; (M eO H -N aO H ) Amax:
210, 265 and 325 nm; Amin: 242 and 295 nm. Mass:
3,4-Dihydro-1 -methyl-
7-(3,4,5-trimethoxybenzoyloxy)-ß-carboline (9)
To a solution of harmalol (200 mg) in pyridine
(3 ml) was gradually added lg of trimethoxybenzoyl
chloride at room temperature and the reaction mix-
ture was kept stirring for about 10 h. The reddish
residue left on removal of pyridine under vacuum,
was repeatedly extracted out with warm 10% acetic
acid. The acidic extract was ammoniated and the re-
sulting yellow precipitate was filtered and washed
upto neutral pH. The nearly colourless precipitate
crystallized out from methanol in fine needles, m.p.
114 °C (yield 55%). IR (KBr) vmax: 3360 (indolic
NH ), 1720 (C = 0 ) and 1625 (aromatic C =C). UV
(M eOH) Amax: 215, 257 and 318 nm; Amin: 235 and
285 nm; (M eO H -H C l) Amax: 215, 257 and 352 nm;
Amln: 245 and 300 nm; (M eOH—NaOH) Amax: 208,
253 and 365 nm; Amin: 239 and 314 nm. Mass: M^ =
394.1529 (calcd. for C22H22N2Os = 394.1528). Other
important fragments at m/e 379, 363, 227, 199, 195
(B .P.), 183, 182 and 167. lU NMR (Table II).
M+
=
369.11507 (calcd. for C19H 19N 3 0 3S
=
369.11468). Other important peaks at m/e 228 (B .P.),
213, 141 and 77. ]H NMR (Table II).
8-(N-Benzenesulfonyl-N-methyl)amino-3,4-dihydro-
7-methoxy-l -methyl-ß-carboline (7)
7 was prepared from 100 mg of 6 following the
procedure described for 3, in about theoretical yield,
as yellow short rods, m.p. 210 (ethyl acetate-petrole-
um ether 1:1). IR (CHC13) vmax: 3400 (indolic NH ),
Table II. 'H NMR spectral data.
9*
Protons
6 (d, = TFAA)
The authors are grateful to Dr. Kehrbach of Kali
Chemie (West Germany) for carrying out phar-
macological tests of 3,4-dihydro-l-methyl-7-(3,4,5-
2.9 (s)
3.4 (s)
2.26
C ,—CH,
OCH,
c 4- h
3.96 (s, 3xO C H ,)
2.73 (m)
3.86 (m)
-
6.83-7.66 (m)
9.33 (br)
-
-
n - c h
2
trimethoxybenzoyloxy)-/3-carboline
and
N-ben-
Q - H
Aromatic-H
Indolic NH
6.9 (d, A 6 = 8 cps)
7.7 (m)
8 . 0 (br, s)
zenesulfonyltetrahydroharmine derivatives. One of
us (S.B.) wishes to express grateful thanks to the
University Grants Commission and Pakistan Science
Foundation for successive provision of research fel-
lowships in the course of this work.
*
‘H NMR recorded in CDC1,; all values are in 6 (ppm)
relative to TMS.
- 10.1515/znb-1986-1219
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Siddiqui
