8
52
Russ.Chem.Bull., Int.Ed., Vol. 50, No. 5, May, 2001
Ozeryanskii et al.
reported previously.17 Í NMR (CD CN), δ: 3.35 (s, 3 Í,
1
solutions and which does not possess the exact melting point.
3
Found (%): Ñ, 73.30; H, 7.14. C13H15N . Calculated (%):
Ñ(3)NMe); 3.58 (br.s, 6 Í, Ñ(1)NMe ); 4.97 (br.s, 2 Í, Í(2));
3
2
C, 73.21; H, 7.09. 1Í NMR, δ: 1.45 (s, 6 Í, CMe ); 3.5 (br.s,
7.07 and 7.59 (both dd, 1 Í each, Í(4), Í(6), J4,5 = 7.4 Hz,
J5,6 = 8.2 Hz, J4,6 = 1.1 Hz); 7.66 (m, 2 Í, Í(5), Í(8)); 7.86
and 8.07 (both br.d, 1 Í each, Í(9), Í(7), J8,9 = 7.7 Hz,
J7,8 = 8.3 Hz).
Salt 4 was prepared from dihydroperimidine 3 (0.5 mmol)
and MeI (2 mL) (see Table 1). The iodomethane was removed
and the crystals were washed three times with anhydrous ether.
Compound 4 was obtained as bright yellowish-brown crystals,
m.p. 147148 °Ñ (from anhydrous MeCN). It decomposed on
melting to form the initial components. Found (%): Ñ, 52.01;
2
2
1
7
Í, NH ); 4.15 (br.s, 2 Í, 2 NH); 6.41 and 6.49 (both d,
Í each, Í(4), Í(9), J4,5 = 7.7 Hz, J8,9 = 7.4 Hz); 6.63 and
2
.12 (both d, 1 Í each, Í(5), Í(7), J = 8.3 Hz); 7.24 (t, 1 Í,
7
,8
1
Í(8)). IR (CHCl ), ν/cm : 3390, 3330, 3280 (NH).
3
,2,2,3-Tetramethyl-2,3-dihydroperimidines (general proce-
1
dure). Ground KOH (0.224 g, 4 mmol) was added to a solution
of dihydroperimidine 8 (1 mmol) in DMF (2 mL) and then
MeI (0.25 mL, 4 mmol) was added in one portion with stirring.
The reaction mixture was heated at 7585 °Ñ, stirred during
the required time (see below), diluted by a factor of three with
water without cooling, and extracted with hot n-hexane
H, 6.10; I, 35.33. C16H21IN . Calculated (%): C, 52.18; H, 5.75;
2
1
I, 34.46. Í NMR (CD CN), δ: 1.34 and 2.11 (both s, 3 Í each,
3
(
4½10 mL). The hexane was removed and the residue was
CMe ); 3.26 and 3.28 (both s, 3 Í each, Ñ(8)NMe ); 3.68 (s,
2
2
crystallized from a suitable solvent or chromatographed on
silica gel (Aldrich, 70230 mesh, 60 Å, CHCl3 as the eluent).
3 Í, Ñ(1)NMe); 7.17 and 7.62 (both dd, 1 Í each, Í(7), Í(5),
J5,7 = 1.3 Hz, J6,7 = 7.3 Hz); 7.67 (m, 2 Í, Í(3), Í(6)); 7.96
and 8.08 (both d, 1 Í each, Í(2), Í(4), J2,3 = 7.6 Hz,
J3,4 = 8.4 Hz).
1,8-Diamino-N,N,N´-trimethylnaphthalene (15) was ob-
tained as hydroiodide in quantitative yield upon heating of salt
4 (0.5 mmol) in water or another moist solvent (MeCN,
alcohol, or DMF) (2 mL) for 510 min. Alkalization of the
solution afforded free base 15 as a colorless oil readily soluble
in dilute mineral acids.18 Hydroiodide 15HI existed as needle-
like yellowish crystals (from MeCN), t.decomp. 170 °Ñ; it
deliquesces in air. Found (%): Ñ, 47.39; H, 5.35; I, 39.22.
1
,2,2,3-Tetramethyl-2,3-dihydroperimidine (3). The time
of heating was 50 min. The yield was 90%. The properties of
the compound are identical with those reported in the litera-
ture.10 1Í NMR, δ: 1.39 and 2.94 (both s, 6 Í each, CMe2,
2
2
NMe); 6.59 (dd, 2 Í, Í(4), Í(9), J4,5 = 7.6 Hz); 7.19 (dd,
Í, Í(6), Í(7), J4,6 = 0.9 Hz); 7.31 (t, 2 Í, Í(5), Í(8),
J5,6 = 8.5 Hz).
1
,2,2,3-Tetramethyl-5-nitro-2,3-dihydroperimidine (9). The
time of heating was 1 h. The yield was 80%. Brick-red crystals,
m.p. 122123 °Ñ (from 95% EtOH). Found (%): Ñ, 66.54;
H, 6.28. C15H17N O . Calculated (%): C, 66.40; H, 6.32.
C13H17IN . Calculated (%): C, 47.58; H, 5.22; I, 38.67.
2
3
2
1
1
Í NMR, δ: 1.34 (s, 6 Í, CMe ); 2.87 and 2.95 (both s,
Í NMR, (CD CN), δ: 2.99 (s, 6 Í, Ñ(1)NMe ); 3.07 (s, 3 Í,
2
3
2
3
Í each, C(1)NMe and C(3)NMe); 6.65 (br.d, 1 Í, Í(9),
Ñ(8)NMe); 7.67 (m, 2 Í, Í(3), Í(6)); 7.78 (dd, 1 Í, Í(7),
J6,7 = 7.5 Hz, J5,7 = 1.2 Hz); 7.85 (dd, 1 Í, Í(2), J2,3 = 7.6 Hz,
J2,4 = 1.0 Hz); 8.01 (m, 2 Í, Í(4), Í(5), J3,4 = 8.1 Hz,
J5,6 = 8.0 Hz); 12.6 (br.s, 2 Í, NH).
J8,9 = 8.4 Hz); 7.11 (d, 1 Í, Í(4), J4,6 = 2.1 Hz); 7.33 (t, 1 Í,
Í(8), J7,8 = 7.9 Hz); 7.78 and 7.97 (both d, 1 Í each,
Í(7), Í(6)).
1
,2,2,3-Tetramethyl-6-nitro-2,3-dihydroperimidine (10).
1,8-Bis(methylamino)naphthalene (6). A solution of
The time of heating was 1.5 h. The yield was 75%. Needle-like
cherry-red crystals, m.p. 161162 °Ñ (from 95% EtOH).
dihydroperimidine 3 (0.1 mmol) in 20% HCl (2 mL) was
refluxed for 1 h. Then the reaction mixture was cooled, neutral-
ized with a 10% solution of ÊÎÍ, and extracted with n-hexane.
Chromatographically pure diamine 6 was obtained in quantita-
tive yield as colorless crystals, m.p. 102103 °Ñ.22
Found (%): Ñ, 66.47; H, 6.24. C15H17N O . Calculated (%):
3
2
C, 66.40; H, 6.32. 1Í NMR, δ: 1.38 (s, 6 Í, CMe ); 2.84 and
2
3
.01 (both s, 3 Í each, C(1)NMe and C(3)NMe); 6.32 (d, 1 Í,
Í(4), J4,5 = 9.1 Hz); 6.64 (br.d, 1 Í, Í(9), J8,9 = 8.0 Hz); 7.45
dd, 1 Í, Í(8), J7,8 = 8.8 Hz); 8.33 and 8.34 (both d,
Í each, Í(7), Í(5), J7,9 = 0.5 Hz).
,3-Dimethyl-2,3-dihydroperimidines 13 were prepared ac-
1,8-Diaminonaphthalene (7, R = H). A suspension of
dihydroperimidine (8, R = H) (0.1 mmol) in 46% HBr (2 mL)
was refluxed for 1.5 h. Then the reaction mixture was cooled,
neutralized with a 10% solution of ÊÎÍ, and extracted with
n-hexane. Diamine 7 was obtained in quantitative yield; its
properties are identical with those of the authentic sample.
Perimidine 16 (see Scheme 7). A mixture of dihydro-
perimidine 8 (R = H) (0.1 mmol), 85% HCOOH (0.5 mL),
and 46% HBr (1.5 mL) was refluxed for 1.5 h. Then the yellow-
brown solution was cooled and neutralized with concentrated
NH3 until a persistent odor appeared. The yellow-green pre-
cipitate of perimidine that formed was filtered off, washed with
water, and dried in air. The yield was 97%, m.p. 223224 °Ñ.26
1,8-Bis(dimethylamino)naphthalenes (12). Iodomethane
(
1
1
cording to a procedure reported previously15 from the corre-
sponding 1,8-diaminonaphthalenes. The use of this procedure
in the case of trimethyl derivative 15 in the presence of a
formaldehyde solution and NaBH4 taken in amounts four times
1
5
larger than those reported in the literature made it possible to
obtain 1,8-bis(dimethylamino)naphthalene (1) in a yield of up
to 78% (see Scheme 7).
1
,3-Dimethyl-2,3-dihydroperimidine (13, R = H). The yield
was 93%. The properties of the compound are identical with
those published in the literature.16,17 1Í NMR, δ: 3.03 (s, 6 Í,
2
NMe); 4.18 (s, 2 Í, CH ); 6.55 (dd, 2 Í, Í(4), Í(9),
(2 mL) was added to a solution of dihydroperimidine 3
2
J4,5 = 7.7 Hz); 7.23 (dd, 2 Í, Í(6), Í(7), J4,6 = 0.9 Hz); 7.35
t, 2 Í, Í(5), Í(8), J5,6 = 8.4 Hz).
,3-Dimethyl-5-nitro-2,3-dihydroperimidine (13, R = 5-NO ).
(0.1 mmol) in DMF (5 mL). Then the reaction mixture was
stirred at 70 °Ñ for 4 h and diluted with an equal amount of
ether. Hydroiodide of diamine 1 that formed was filtered off
and decomposed with a 20% solution of KOH. After extraction
with n-hexane and removal of the solvent, 1,8-bis(dimethyl-
amino)naphthalene (1) was obtained in 95% yield as virtually
colorless crystals, m.p. 4748 °Ñ.18 The use of salt 4 or
trimethyl derivative 15 instead of compound 3 gave an analo-
gous result. The same "proton sponge" can be prepared by
reduction of quaternary salt 14 with NaBH4 in aqueous alco-
hol, aqueous THF, or MeOH (in all cases, the yields were
higher than 90%, see Scheme 7).
(
1
2
The yield was 33%. Red crystals, m.p. 125127 °Ñ (from
n-hexane). Found (%): Ñ, 64.53; H, 5.47. C13H13N O . Calcu-
3
2
lated (%): C, 64.19; H, 5.39. 1Í NMR, δ: 3.01 and 3.07 (both s,
Í each, C(1)NMe and C(3)NMe); 4.22 (s, 2 Í, CÍ ); 6.68
3
2
and 7.16 (both d, 1 Í each, Í(9), Í(4), J4,6 = 2.2 Hz,
J8,9 = 7.8 Hz); 7.33 (d, 1 Í, Í(7), J7,8 = 8.1 Hz); 7.44 (t, 1 Í,
Í(8)); 8.10 (d, 1 Í, Í(6)).
1
,1,3-Trimethyl-2,3-dihydroperimidinium iodide (14) was
prepared from compound 13 (R = H) according to a procedure