KR850001474B1 - Process for the preparation of 1-phenyl-3(2,2-dialkoxy)ethyl-3,6-diazaheptane-4,7-dione derivation - Google Patents

Abstract

The title compounds I (R1 = H, lower alkyl, C3-7 cycloalkyl; R2=R3=H, OH, C1-6 alkoxy, C1-6 aromatic hydrocarbon; R4 = methyl, ethyl), which are useful as starting materials for 2-acyl-4-oxo1,3,4,6,7,11b hexahydro-4H-pyrazines[2,1-a isoquinoline derivatives used as vermicides, were prepared. Thus, N-(2,2-dialkoxy) ethylpenethylamine was reacted with N-acylglycin to give 1-phenyl-3(2,2-dialkoxy)ethyl- 3,6-diazaheptane-4,7-dione derivatives.

Description

Method for preparing 1-phenyl-3 (2,2-dialkoxy) ethyl-3,6-diazaheptan-4,7-dione derivative

The present invention relates to a method for producing 1-phenyl-3 (2,2-dialkoxy) ethyl-3,6-diazaheptan-4,7-dione derivative represented by the following general formula (I).

In general formula (I), R <_1> is hydrogen, a lower alkyl group, or a C3-C7 cycloalkyl group, R <_2> , R <_3> is hydrogen, a hydroxyl group, a C1-C6 alkoxy group, or C1-C6 aliphatic hydrocarbon And R ₄ is methyl, ethyl.

These compounds are 2-acyl-4-oxo-1,3,4,6,7,11b-hexahydro-4H-pyra represented by the general formula (II), which exhibit potent activity against spheroidism, in particular dystoma and uptake. Gino [2,1-a] isoquinoline derivative is used as a starting material in the gymnastics.

In general formula (II), R <_1> , R <_2> , R <_3> is as same as general formula (I) mentioned above.

Conventional methods of preparing the compound (II) are described in Korean Patent Publications (Publication Nos. 80-31 and 80-89), US Patent Nos. 3,993,760 (1976), Exerientia 33, 1036 (1977), and the like. The methods described in the literature have the drawback of going through the process of preparing the following general formula (III) (IV) (V) compounds, which are difficult to mass produce industrially.

In other words, the general formula (III) compound is hydrogenated at high temperature (100 deg. C) and high pressure (100 atm) in the presence of a catalyst for a Ressert's Compound obtained by reacting isoquinoline with acyl chloride and an alkali metal cyanide. As a result, the safety due to high temperature and high pressure and hydrogen reduction is a problem.

The general formula (IV) compound must also undergo several reactions (6-8,) starting from phenylglyoxal as described in known patents (Korean Patent Publication No. 80-31). Because it is not good, it is not an industrial recipe.

Finally, Experientia 33, 1036 (1977) states that compounds of formula (II) can be prepared starting from compounds of formula (V). Since no data on the confirmation of the structure of the intermediates were described, it was not a practical synthesis method.

Therefore, in the present invention, a method of preparing the compound of formula (II) by synthesizing the compound of formula (I), wherein compound (II) is prepared by a simple cyclization reaction, has been developed.

The preparation method according to the present invention of the compound of formula (I), which is useful for the preparation of compound of formula (II), is as follows.

It is prepared by reacting N- (2,2-dialkoxy) ethylphenethylamine derivative of formula (VI) (prepared by reacting phenethylamine derivative with haloacetaldehyde dialkylacetal) and N-acylglycine.

Example 1

1-phenyl-3 (2,2-diethoxy) ethyl-7-cyclohexyl-3,6-diazaheptan-4,7-dione (I: R ₁ = cyclohexyl, R ₂ = R ₃ = hydrogen, R ₄ = ethyl)

27.3 g (0.1 mole) of N- (2,2-diethoxy) ethyl phenethylamine was reacted with 0.1 mole of N-cyclohexylglycine anhydride (0.1 mole of N-cyclohexylglycine) and 0.1 mole of ethylchloro formate in the presence of triethylamine (Prepared) at 0 ° C and stirred for 30 minutes, followed by stirring at room temperature for 1 hour. Water was added to the reaction solution, washed with dilute hydrochloric acid and aqueous sodium hydroxide solution, and the organic layer was dried, and the solvent was removed to obtain 39 g (97%) of pale yellow viscous liquid.

nmr (CDCL ₃ ) δ: 1.10 (t, 6, CH ₃ ), 1.3-2.5 (m, 10, cyclohexanide)

2.5-4.3 (m, 12, CH), 4.6 (t, 1, CH), 7.2 (S, 5, Benzene Hydrogen)

Claims (1)

N- (2,2-dialkoxy) ethylphenethylamine derivative of formula (VI) and N-acylglycine react with 1-phenyl-3 (2,2-di Alkoxy) ethyl-3,6-diazaheptan-4,7-dione derivative.

In general formula (I) (VI), R <_1> is hydrogen, a lower alkyl group, or a 3-7 cycloalkyl group, R <_2> R <_3> is hydrogen, a hydroxyl group, a C1-C6 alkoxy group, or C1-C6 Aliphatic hydrocarbon, R ₄ is methyl, ethyl.