it is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention claimed . as used herein , the use of the singular includes the plural unless specifically stated otherwise . it will be readily apparent to those skilled in the art that some of the compounds of the invention may contain one or more asymmetric centers , such that the compounds may exist in enantiomeric as well as in diastereomeric forms . unless it is specifically noted otherwise , the scope of the present invention includes all enantiomers , diastereomers and racemic mixtures . some of the compounds of the invention may form salts with pharmaceutically acceptable acids or bases , and such pharmaceutically acceptable salts of the compounds described herein are also within the scope of the invention . the present invention includes all pharmaceutically acceptable isotopically enriched compounds . any compound of the invention may contain one or more isotopic atoms enriched or different than the natural ratio such as deuterium 2 h ( or d ) in place of protium 1 h ( or h ) or use of 13 c enriched material in place of 12 c and the like . similar substitutions can be employed for n , o and s . the use of isotopes may assist in analytical as well as therapeutic aspects of the invention . for example , use of deuterium may increase the in vivo half - life by altering the metabolism ( rate ) of the compounds of the invention . these compounds can be prepared in accord with the preparations described by use of isotopically enriched reagents . the following examples are for illustrative purposes only and are not intended , nor should they be construed as limiting the invention in any manner . those skilled in the art will appreciate that variations and modifications of the following examples can be made without exceeding the spirit or scope of the invention . the iupac names of the compounds mentioned in the examples were generated with acd version 12 . 5 . unless specified otherwise in the examples , characterization of the compounds is performed according to the following methods : nmr spectra are recorded on 300 mhz varian and acquired at room temperature . chemical shifts are given in ppm referenced either to internal tms or to the residual solvent signal . all the reagents , solvents , catalysts for which the synthesis is not described are purchased from chemical vendors such as sigma aldrich , fluka , lancaster , however some known reaction intermediates , for which the cas registry number is mentioned , were prepared in - house following known procedures . usually the compounds of the invention were purified by flash column chromatography . to a solution of ethane - 1 , 2 - diamine ( cas 107 - 15 - 3 ) ( 704 mg , 4 . 5 eq ) in benzene ( 10 ml ) was added a solution of 4 - isothiocyanato - quinoline ( cas 868163 - 42 - 2 ) ( 480 mg , 2 . 61 mmol ) in benzene ( 5 ml ). the resulting mixture was stirred at room temperature for 16 h . the product precipitated as a pale yellow solid , which was filtered to collect the solid washed with ether and gave intermediate 1 . to a solution of 4 - chloro - 1 , 5 - naphthyridin - 3 - amine ( cas 930276 - 73 - 6 ) ( 550 g , 3 . 07 mmol ) in thf ( 10 ml ) was added tea ( 0 . 95 ml , 6 . 76 mmol ) followed by cscl 2 ( 0 . 26 ml , 3 . 4 mmol ) at 0 ° c . the mixture was stirred at room temperature for 2 h . celite ( 2 g ) was added to the reaction mixture , then concentrated and purified by silica gel column chromatography using hexane : etoac ( 7 : 3 ) and gave intermediate 2 ( 360 mg ). to a solution of ethane - 1 , 2 - diamine ( cas 107 - 15 - 3 ) ( 0 . 54 ml , 8 . 12 mmol ) in benzene ( 10 ml ) was added a solution of intermediate 2 ( 360 mg ) in benzene ( 5 ml ). the resulting mixture was stirred at room temperature for 16 h . benzene and excess of ethane - 1 , 2 - diamine were decanted . the product was washed with ethyl - ether and yielded intermediate 3 . intermediate 1 was taken in etoh ( 15 ml ) with mercury oxide ( 618 mg ) and heated at reflux temperature for 4 h . the mixture was cooled to room temperature and filtered through celite . silica gel was added to the filtrate and concentrated and purified by chromatography on silica gel with 5 % nh 3 - meoh : dcm and gave ( 68 mg ) compound 1 as a white solid . 1 h nmr ( methanol - d 6 ) δ : 8 . 54 ( d , j = 5 . 0 hz , 1h ), 8 . 23 ( d , j = 7 . 9 hz , 1h ), 7 . 88 ( d , j = 8 . 5 hz , 1h ), 7 . 61 - 7 . 72 ( m , 1h ), 7 . 41 - 7 . 53 ( m , 1h ), 7 . 05 ( d , j = 5 . 3 hz , 1h ), 3 . 56 ( s , 4h ). intermediate 3 was taken in etoh ( 15 ml ) with mercury oxide ( 422 mg ) and heated at reflux temperature for 2 h . the mixture was cooled to room temperature filtered through celite . silica gel was added to the filtrate concentrated and purified by silica gel chromatography using 5 % nh 3 - meoh : dcm and gave ( 120 mg ) compound 2 . 1 h nmr ( methanol - d 4 ) δ : 8 . 90 ( dd , j = 4 . 1 , 1 . 5 hz , 5h ), 8 . 68 ( s , 1h ), 8 . 36 ( dd , j = 8 . 2 , 1 . 5 hz , 1h ), 7 . 66 ( dd , j = 8 . 5 , 4 . 4 hz , 1h ), 3 . 56 ( s , 4h ). compounds 3 , 4 , 5 , 6 and 7 were prepared in a similar manner to the method described in example 5 for compound 2 starting with the corresponding starting material . the results are tabulated below in table 1 . novel compounds were synthesized and tested for alpha adrenergic activity using the receptor selection and amplification technology ( rsat ) assay ( messier et . al ., 1995 , pharmacol . toxicol . 76 , pp . 308 - 311 ). cells expressing each of the alpha2 adrenergic receptors alone were incubated with the various compounds and a receptor - mediated growth response was measured . the compound &# 39 ; s activity was expressed as its relative efficacy compared to a standard full agonist ( see table 2 ). the compounds of this invention activate alpha 2 receptors .
the present invention relates to novel n - quinoline derivatives , processes for preparing them , pharmaceutical compositions containing them and their use as pharmaceuticals .