Crystal structure of 2,2-diphenyl-4-dimethylaminopentanenitrile,
C19H22N2
C19H22N2, monoclinic, C1c1 (no. 9), a = 8.636(1) Å,
b = 15.162(2) Å, c = 12.807(2) Å, = 106.599(3)°,
V = 1607.1 Å
3
, Z = 4, Rgt(F) = 0.044, wRref(F2
) = 0.088,
T = 120 K.
Source of material
The title compound was synthesized by reaction of 1-dimethyl-
amino-2-chloropropane hydrochloride and diphenylacetonitrile
in the presence of NaOH as a base. 1-dimethylamino-2-chloro-
propane was obtained from the reaction of thionyl chloride and 1-
dimethylamino-2-propanol whose preparation was described
previously [1]. In a typical procedure, a 50 % w/v solution of so-
dium hydroxide in water (12.5 ml, 0.32 mol) was added to a me-
chanically stirred suspension of diphenylacetonitrile (15.0 g,
0.08 mol) and dibenzo-18-crown-6 (0.5 g, cat.) in dimethylsulf-
oxide (12.5 ml). The color rapidly deepened to an orange/brown.
1-Dimethylamino-2-chloropropane hydrochloride (15 g, 0.095mol)
was added in portions over 30 min, this caused the temperature to
rise to 30 °C. After the addition was completed the mixture was
warmed to 45-50 °C (water bath) and stirred for one hour. The
reaction mixture was then allowed to cool to room temperature,
poured into ice/water (250 ml) and extracted with ethyl acetate
(3 × 150 ml). The combined extracts were dried (MgSO4),filtered
and evaporated down to 100 ml. The product was extracted into
1NHCl (100 ml + 50 ml) and then again washed with ethyl ace-
tate. The aqueoussolution was basified with 2Msodium hydrox-
ide and extracted into ethyl acetate (3 × 100 ml). The extracts
were washed with saturated NaClsolution (70ml), dried (MgSO4),
and evaporated down to a yellow oil. This was chilled and titrated
with cold hexane (50 ml) to give the title compound (yield 39 %).
Recrystallization from hexane gave crystals suitable for X-ray
analysis (m.p. 91-92 °C).
Discussion
Racemic methadone, 6-dimethylamino-4,4-diphenyl-3-hepta-
none, is used as a maintenance drug in the treatment of heroin
addiction and severe pain symptoms. It also helps to combat the
spread of HIV by reducing injection of heroin [2]. These and
other unique properties of methadone led us to synthesize the
methadone. In a multi-step preparation of methadone, the syn-
thesis of 2,2-diphenyl-4-dimethyl aminopentanenitrile is a very
important step in which we gained a series of crystals.
The crystal structure of the title compound is built up by only the
C19H22N2 molecules within which all bond lengths are almost in
normalranges(figure, top).C6 atom issubstituted with two phenyl
groups and the C8–C6–C14 angle is 108.2(4)°. The C7–C6–C14
angle of 104.3(2)° and C2–C1–C16 angle of 110.8(2)° deviate
slightly from the ideal value of 109.5°. The other bond angle
around C6 are C5–C6–C7 (108.6(2)°), C5–C6–C8 (111.0(2)°)
andC5–C6–C14 (112.8(2)°), which showssmallsteric strains be-
tween the substituents. The cyanide group twists very slightly out
of the line of C1—C2 as seen by the C6–C7–N1 angle of
173.4(2)°. The planes of the two phenyl rings on C6 are oriented
differently to each other with one in a horizontal and the other in a
vertical manner. The arrangement of two molecules in the unit
cell is in a fashion that intermolecular - stacking interactions
between two horizontal phenyl groups are achieved. These inter-
actions were not observed for the vertical phenyl groups (figure,
bottom).
C19H22N2
C19H22N2, monoclinic, C1c1 (no. 9), a = 8.636(1) Å,
b = 15.162(2) Å, c = 12.807(2) Å, = 106.599(3)°,
V = 1607.1 Å
3
, Z = 4, Rgt(F) = 0.044, wRref(F2
) = 0.088,
T = 120 K.
Source of material
The title compound was synthesized by reaction of 1-dimethyl-
amino-2-chloropropane hydrochloride and diphenylacetonitrile
in the presence of NaOH as a base. 1-dimethylamino-2-chloro-
propane was obtained from the reaction of thionyl chloride and 1-
dimethylamino-2-propanol whose preparation was described
previously [1]. In a typical procedure, a 50 % w/v solution of so-
dium hydroxide in water (12.5 ml, 0.32 mol) was added to a me-
chanically stirred suspension of diphenylacetonitrile (15.0 g,
0.08 mol) and dibenzo-18-crown-6 (0.5 g, cat.) in dimethylsulf-
oxide (12.5 ml). The color rapidly deepened to an orange/brown.
1-Dimethylamino-2-chloropropane hydrochloride (15 g, 0.095mol)
was added in portions over 30 min, this caused the temperature to
rise to 30 °C. After the addition was completed the mixture was
warmed to 45-50 °C (water bath) and stirred for one hour. The
reaction mixture was then allowed to cool to room temperature,
poured into ice/water (250 ml) and extracted with ethyl acetate
(3 × 150 ml). The combined extracts were dried (MgSO4),filtered
and evaporated down to 100 ml. The product was extracted into
1NHCl (100 ml + 50 ml) and then again washed with ethyl ace-
tate. The aqueoussolution was basified with 2Msodium hydrox-
ide and extracted into ethyl acetate (3 × 100 ml). The extracts
were washed with saturated NaClsolution (70ml), dried (MgSO4),
and evaporated down to a yellow oil. This was chilled and titrated
with cold hexane (50 ml) to give the title compound (yield 39 %).
Recrystallization from hexane gave crystals suitable for X-ray
analysis (m.p. 91-92 °C).
Discussion
Racemic methadone, 6-dimethylamino-4,4-diphenyl-3-hepta-
none, is used as a maintenance drug in the treatment of heroin
addiction and severe pain symptoms. It also helps to combat the
spread of HIV by reducing injection of heroin [2]. These and
other unique properties of methadone led us to synthesize the
methadone. In a multi-step preparation of methadone, the syn-
thesis of 2,2-diphenyl-4-dimethyl aminopentanenitrile is a very
important step in which we gained a series of crystals.
The crystal structure of the title compound is built up by only the
C19H22N2 molecules within which all bond lengths are almost in
normalranges(figure, top).C6 atom issubstituted with two phenyl
groups and the C8–C6–C14 angle is 108.2(4)°. The C7–C6–C14
angle of 104.3(2)° and C2–C1–C16 angle of 110.8(2)° deviate
slightly from the ideal value of 109.5°. The other bond angle
around C6 are C5–C6–C7 (108.6(2)°), C5–C6–C8 (111.0(2)°)
andC5–C6–C14 (112.8(2)°), which showssmallsteric strains be-
tween the substituents. The cyanide group twists very slightly out
of the line of C1—C2 as seen by the C6–C7–N1 angle of
173.4(2)°. The planes of the two phenyl rings on C6 are oriented
differently to each other with one in a horizontal and the other in a
vertical manner. The arrangement of two molecules in the unit
cell is in a fashion that intermolecular - stacking interactions
between two horizontal phenyl groups are achieved. These inter-
actions were not observed for the vertical phenyl groups (figure,
bottom).