SU1231054A1 - Method of producing 1-acyl-5-alkoxypyrazolidines - Google Patents

Description

one

This invention relates to a novel process for the preparation of novel cyclic hydrazine derivatives, namely, 1-acyl-5-alkoxypyrazolidines.

formulas

RiO-p

Ya2so- c: d-ns

SbH5

where r is

1 - SNZ

Cjhg

2

sn

3

Rj H, CH,

which can be used in organic chemistry and in the synthesis of intermediate products of biologically active substances.

The purpose of the invention is a new way.

Calculated,%: C, 72.97; H 9.25. Example 3. 1-Propionyl-5-metroxy-2-phenyl-3-methylpyrazolidine (1c). 15 To a solution of 1.17 g (5 mmol) of 1- -propionyl-5-hydroxy-2-phenyl-3-methylpyrazolidine in 20 ml of methanol was added 8 ml of water and 5 ml of hydrochloric acid. A day later, neutralized with a solution

obtaining new 1-acyl-5-alkoxypyra-0 sodium carbonate, extracted 3 times

chloroform, the solvent is evaporated in vacuo. The residue is chromatographed

zolidines.

Example 1. 1-Acetyl-5-propoxy-2-phenyl-3-methylpyrazolidine (1a).

1.1 g (5 mmol) of 5-hydroxy-gy-tg g are dissolved,

-1-acetyl-2-fensh1-3-methylpyrazodidine 25 with Rf 0.75. After evaporation of the solution in 10 ml of propyl alcohol and 20 mg of KU-2 ion-exchange resin is added in

on a column of SiO 40x100 in the benzene-ethyl acetate system 2: 3, collecting the fraction

JiiS (, 5 8 C

H-form. The reaction mass is stirred for 5 hours, the resin is separated, the solvent is evaporated, the residue is evaporated in vacuum at a temperature not higher than 40 ° C. The yield of the compound (1a) is 0.93 g (74%), m.p. 55-56 ° C. IR spectrum: 1685 cm- (). The spectrum of the PNR (CC1J: 0.88 (GH, t, SNd-Pr, J = 8 Hz); 1.28 (GH, d H – CHd, J = 6 Hz); 1.48-1.62 (2H, d, 4-H, J 8 Hz), 1798 (3N, s,); 2.00- 2.32 (2H, m, CH2-Pr); 3.48-3.66 (2H, q, CH, 0) ; 4.00-4.16 (1H, m, 3-H); 5.68 - 5.84 (.1H, dd, 5-H, J - - - 6.75-7.24 (5H, m , Ar) m, d.

Found,%: C 68.74; H 8.77

C, s HjjNjGj

Calculated,%: C 68.70; H 8.40.

Example 2. 1-Acetyl-2-phenyl-5-benzyloxypyrazolidine (16).

1.03 g (5 mmol) of 1-acetyl-5-hydroxy-2-phenylpyrazoline is dissolved in 30 ml of acetonitrile and 0.5 ml (5 mmol) of freshly distilled benzyl alcohol and 20 mg of KU-20 ion-exchange resin are added. 2 in H-form. The solution is stirred for 10 hours, the resin is separated, the solvent is evaporated in vacuo, and the residue is chromatographed on a SiO column. 40x100 in the benzene-ethyl acetate system 1: 1, collecting fraction c, 77 After evaporation of the solvent solvent in vacuum, a yellowish oil is formed.

Yield of compound (1c) 0.88 g (70%), IR spectrum: 1695 cm (), Spectrum 30 PNR (CC1): 1.10 (G, t, CH3-Pr, J 8 Hz); 1.28 (3N, d, 3-CH5, L = 7 Hz); 2.21 (2H, m, 4-H): 2.38 (2H, q, CH4CO, J = 8 Hz); 3.57 (3N, s, OCHD; 4J5 (1H, m, 3-H); 5.83 (1H, dd, 5-H,

35

J, 5 6 Hz, 31 4 Hz); 6.9-7.4

40

(5H, m, Ar).

Found,%: C 67.56; H 8.36;

C ,, H ,,,.

Calculated,%: C 67.80; H 8.07.

Example 4. 1-Acetyl-2-phenyl-5-methoxypyrazolidine.

Dissolve 0.5 g (2.5 mmol) of 1- -acetyl-5-hydroxy-2-phenylpyrazolidine in 5 ml of methanol, add 0.01 g., Dowex-50 ion-exchange resin (H-form), the mixture is stirred for 6 h, the catalyst is separated, the alcohol is evaporated, and purified by sublimation in vacuo. The output of 0.35 g (65%), so pl. .

JK-spectrum: 1690 cm ().

Found,%: N 13.01.

Calculated,%: N 12,73.

,, N, 0

Example 5. 1-Acetyl-2-phenyl-5-benzyloxypyrazolidine.

Analogously to Example 2, methylene chloride was taken as numerical solvent. The yield of the target product is 0.67 g (46%).

50

231054 2

These are large white crystals that recrystallize and Aether.

Compound (16) yield 1 g (68%),

m.p. 86-87 ° C. IR spectrum: 1685 cm

five (). Spectrum of the NDP (GC1): 2.01 (MN, s,

CH CO), 2.05-2.34 (2H, m, 4-H); 3.483, 80 (2H, m, 3-H); 4.70 (2H, c..PhCH, j);

. 5.81-6.0 (1H; dd, 5H, J 4 Hz);

6.90-7.45 (10H, m, Ar) m, d. 0 Found%: C 73.00; H 6.71. C, 8H, N, 0.

Calculated,%: C, 72.97; H 9.25. Example 3. 1-Propionyl-5-metroxy-2-phenyl-3-methylpyrazolidine (1c). 15 To a solution of 1.17 g (5 mmol) of 1- -propionyl-5-hydroxy-2-phenyl-3-methylpyrazolidine in 20 ml of methanol was added 8 ml of water and 5 ml of hydrochloric acid. A day later, neutralized with a solution

 „Yy" -tg g,

on a column of SiO 40x100 in the benzene-ethyl acetate system 2: 3, collecting the fraction

with Rf 0.75. After evaporation of the solution

The solvent in vacuo forms a yellowish oil.

Compound (1c) yield 0.88 g (70%), IR spectrum: 1695 cm (), Spectrum of the NDP (CC1): 1.10 (G, t, CH3-Pr, J 8 Hz); 1.28 (3N, d, 3-CH5, L = 7 Hz); 2.21 (2H, m, 4-H): 2.38 (2H, q, CH4CO, J = 8 Hz); 3.57 (3N, s, OCHD; 4J5 (1H, m, 3-H); 5.83 (1H, dd, 5-H,

J, 5 6 Hz, 31 4 Hz); 6.9-7.4

(5H, m, Ar).

Found,%: C 67.56; H 8.36;

C ,, H ,,,.

Calculated,%: C 67.80; H 8.07.

Example 4. 1-Acetyl-2-phenyl-5-methoxypyrazolidine.

0.5 g (2.5 mmol) of 1- -acetyl-5-hydroxy-2-phenylpyrazolidine is dissolved in 5 ml of methanol, 0.01 g of Dowex-50 ion-exchange resin is added, stirred 6 the catalyst is separated, the alcohol is evaporated and purified by sublimation in vacuo. The output of 0.35 g (65%), so pl. .

JK-spectrum: 1690 cm ().

Found,%: N 13.01.

Calculated,%: N 12,73.

,, N, 0

Example 5. 1-Acetyl-2-phenyl-5-benzyloxypyrazolidine.

Analogously to Example 2, methylene chloride was taken as numerical solvent. The yield of the target product is 0.67 g (46%).

Claims (1)

METHOD FOR PRODUCING 1-Acyl-5-Alkoxypirazolidines of the general formula where 1C is n-C ₃ H ₇ , C ₆ H _$ CH ₂ , CH ₃ ; R, - CH ₃ , C ₂ H ₅ ; R ₃ - H, CH ₃ , characterized in that 1-acyl-5-hydroxypyrazolidines of the General formula With ₆ n ₅ where R ₂ and R ₃ have the indicated meanings, they are reacted with an equimolar amount of the corresponding alcohol in the presence of an organic solution of Acetonitrile, methylene chloride, or with a 30-90-fold excess. lump of alcohol at room temperature in the presence of an acid catalyst Q