Synthesis, Spectroscopic Characterization and Structure-Activity Relationship
and further yield (see Fig. 1). Also, compounds 1, 6, 7 and 10
were reported before [10,11].
diethylamine instead of methylamine. Red liquid, yield: 80%;
31P{1H}-NMR, δ (ppm): 79.7 (s) 31P NMR, δ (ppm): 79.7 (m).
3
Compound 1. Ammonium hydroxide (16.92 g, 287.6
mmol) was slowly added into a solution of O,O-dimethyl
phosphorochloridothioate (20 g, 124.5 mmol) in 50 ml
methylene chloride and the obtained mixture was stirred at 0
°C. The mixture was heated to 44 °C by gentle refluxing.
Then, it was cooled down to 25 °C by ice bath. The mixture
was stirred for an additional 1 h, leaving two separate phases.
Then, the organic phase was washed with 3 ml of water and
the aqueous phase was washed twice with 5 ml of methylene
chloride. Then, the aqueous phase was removed, the organic
phase was dried with a little sodium sulfate and the solvent
was left to evaporate in vacuum. Then the solvent was stripped
to obtain a colorless oily product: Colorless oil, yield: 99%;
31P{1H}-NMR, δ (ppm): 76.2 (s); 31P NMR, δ (ppm):
1H NMR, δ (ppm): 1.10 (t, JH-H = 7.0 Hz, 6H, 2CH3), 3.21
3
(dq, 4H, NCH2) 3.62 (d, JP-H = 13.8 Hz, 6H, 2OCH3).
13C NMR, δ (ppm): 14.1 (d, 3JP-C = 1.9 Hz, 2C, CH3), 40.1 (d,
2JP-C = 4.40 Hz, 2C, CH2), 53.0 (d, 2JP-C = 5.0 Hz, 2C, OCH3).
Compound 5. This compound was prepared by the similar
procedure applied to prepare the compound 2 using O,O-
diethyl phosphorochloridothioate instead of O,O-dimethyl
phosphorochloridothioate. Yellow liquid, yield: 65%;
31P{1H}-NMR, δ (ppm): 73.23 (s). 31P NMR, δ (ppm): 73.2
1
3
(m). H NMR, δ (ppm): 1.33 (t, 6H, JH-H = 7.0 Hz, 2CH3),
3
2.61 (d, 3H, JP-H = 13.0 Hz, NCH3) 3.02 (brs, 1H, NH) 4.06
(dq, 4H, 2CH2). 13C NMR, δ (ppm): 15.8 (d, JP-C = 8.2 Hz,
3
1C, CH3), 15.8 (d, 3JP-C = 8.2 Hz, CH3), 16.1 (d, 3JP-C = 7.5 Hz,
CH3), 27.5 (d, 2JP-C = 3.1 Hz, 1C, NCH3), 62.5 (s, 1C, OCH3),
62.6 (s, 1C, OCH3).
1
76.24(m). H NMR, δ (ppm): 3.23 (brs, 2H, NH2), 3.74 (d,
3JP-H = 13.8 Hz, 3H, OCH3); 13C NMR, δ (ppm): 53.1 (d,
Compound 6. In 0.1 M scale, dimethyl sulfate (3.15 g,
25.1 mmol) was slowly added into a solution of O,O-dimethyl
phosphoramidothioat (1) (15 g, 106.15 mmol) in 30 ml
chloroform and the obtained mixture was stirred at 56 °C. The
solvent was left to evaporate in vacuum: Colorless crystal,
yield: 90%; m.p: 43 °C. 31P{1H}-NMR, δ (ppm): 37.4 (s);
2JP-C = 5.0 Hz, 1C, OCH3).
Compound 2. 25 ml of N-methyl amine buffer was slowly
added into a solution of O,O-dimethyl phosphorochlorido-
thioate (8 g, 50 mmol) in 20 ml dicholoromethane at 0 °C.
Then, N-methyl amine (12 g, 150 mmol, pH = 9.1) was slowly
added into the mixture at 35 °C for an additional 20 min. The
mixture reaction was heated by gentle refluxing for 40 min.
The solvent was left to evaporate in vacuum. Then, the flash
gradient chromatography method was used for the purification
of the product (silicagel, hexane-ethyl acetate 8:2). Colorless
liquid, yield: 96%; 31P{1H}-NMR, δ (ppm): 77.2 (s). 31P-
1
31P NMR, δ (ppm): 37.4 (m). H NMR, δ (ppm): 2.46 (d,
3JP-H = 14.8 Hz, 3H, SCH3), 3.23 (brs, 2H, NH2), 3.76 (d,
3JP-H = 12.8 Hz, 3H, OCH3); 13C NMR, δ(ppm): 12.7 (d,
2JP-C = 3.8 Hz, 1C, SCH3), 52.8 (d, 2JP-C = 5.7 Hz, 1C, OCH3).
Compound 7. A solution of N-methyl O,O-dimethyl
phosphoramidothioate (3 g, 20 mmol), methyl iodid (3 g),
acetonitril saturated solution to KI (2 ml) and 18-Crown-6 (0.1
g) in 20 ml dicholoromethane was added into a glass pressure
vessel. The mixture was heated in an oil bath at 80 °C for 30-
45 min. After 5 h of stirring, the solvent was left to cool down
and evaporate in vacuum. Then, the flash gradient
chromatography method was used for purification of the
product (silicagel, hexane-ethyl acetate 9:1). Yellow liquid,
yield: 92%; 31P{1H}-NMR, δ (ppm): 38.6. 31P NMR, δ (ppm):
NMR, δ (ppm): 77.2 (m). 1H NMR, δ (ppm): 2.38 (dd, 3JP-H
14.6 Hz, 3JH-H = 1.6 Hz, 3H, NHCH3), 3.34 (brs, 1H, NH) 3.46
=
3
3
(dd, JP-H = 15.4 Hz, JH-H = 1.8, 6H, OCH3) [12], 13C NMR,
δ (ppm): 27.9 (d, 2JP-C = 3.4 Hz, 1C, NHCH3), 53.4 (d, 2JP-C
=
4.9 Hz, 2C, OCH3).
Compound 3. This compound was prepared by the similar
procedure applied to the compound 2 using dimethylamine
instead of methylamine. Yellow liquid, yield: 91%; 31P{1H}-
NMR, δ (ppm): 80.9 (s). 31P NMR, δ (ppm): 80.9 (m).
1
3
38.6 (m). H NMR, δ (ppm): 2.10 (d, JP-H = 14.2 Hz, 3H,
3
3
3
1H NMR, δ (ppm): 2.77 (d, JP-H = 11.5 Hz, 6H, NCH3), 3.62
SCH3), 2.42 (dd, JP-H = 14.1 Hz, JH-H = 5.1 Hz, 3H, NCH3),
3
3
(d, JP-H = 13.0 Hz, 6H, OCH3), 13C NMR, δ (ppm): 37.1 (d,
3.61 (d, JP-H = 24.0 Hz, 3H, OCH3). 13C NMR, δ (ppm): 12.0
2JP-C = 3.8 Hz, 2C, NCH3), 53.2 (d, 2JP-C = 5.0 Hz, 2C, OCH3).
Compound 4. This compound was also prepared by the
similar procedure applied to prepare the compound 2 using
(d, 2JPC = 1.9 Hz, SCH3), 27.0 (s, NHCH3), 52.68 (d, 2JPC = 5.7
Hz, OCH3).
Compound 8. This compound was prepared by the similar
719