the reactive dyestuff compound of formula ( ia ) of the present invention can be prepared by the following process . preferably , the reactive dyestuff compound of formula ( ia ) is synthesized by reacting the following compounds ( a ), ( b ), and ( c ) together in the molar ratio of 1 : 1 : 2 , r 6 and r 7 each independently are selected from the group consisting of halogen , hydroxyl , carboxyl , sulfo , c 1 - 4 alkyl , c 1 - 4 alkoxy , and c 2 - 6 alkoxycarbonyl ; p and q are integers independent of one another between 0 to 2 ; q 3 is selected from the group consisting of — nh — co — chx — ch 2 — x , — nh — co — cx ═ ch 2 , — conh ( ch 2 ) n — so 2 — y , and — so 2 — y , wherein y is — ch ═ ch 2 or — ch 2 ch 2 u ; u a leaving group which is eliminable by a base ; and x is halogen ; and the diazotizing salt compounds of ( a ) and ( c ) are synthesized by common method , which is generally proceeded in a nitrite acidic solution at low - temperature . in the coupling reaction between the diazotizing salt compounds and the ( b ) compound , the first diazotizing salt is generally coupling on the 2 - position of the phenyl group in the ( b ) compound while the second and third diazotizing salts are coupling on the 4 - position and 6 - position of the phenyl group in the ( b ) compound , respectively . the ideal condition for the coupling reaction is in a condition of ph 2 ˜ 7 at normal temperature , and preferably , is ph 3 ˜ 7 at a temperature in the range of 5 ˜ 25 ° c . hereinafter , the present invention will be further explained . however , it is to be understood that the examples below are only for illustrated , but not to limit the scope of the present invention . the compounds are represented in the form of free acid . however , in practice , they often exist as metallic salts , and most likely alkaline metallic salts , particularly sodium salts . unless otherwise stated , the parts and percentage used in the following examples are based on weight , and the temperature is in celsius degree (° c .). 28 parts of 2 - sulfonic - 4 - β - sulfatoethylamino - aniline are dispersed in 300 parts of ice water , and then 22 . 8 parts of 32 % hcl are added therein with thorough stirring , followed by the addition of 6 . 9 parts of sodium nitrite with continuous stirring at a temperature in the range of 0 ° c . to 5 ° c . until the diazotization is accomplished . 15 . 2 parts of 3 , 5 - diaminobenzoic acid are added to an aqueous solution ( 100 ml ) containing 22 . 8 parts of 32 % hcl with stirring for 30 minutes at a temperature in the range of 0 ° c . to 5 ° c ., followed by the addition of the diazotizing compound afforded by the aforementioned process with continuous stirring until the coupling reaction is accomplished . 56 . 2 parts of 4 - β - sulfatoethylsulfone - aniline are dispersed in 580 parts of ice water , and then 45 . 6 parts of 32 % hcl aqueous solution are added therein with thorough stirring , followed by the addition of 13 . 8 parts of sodium nitrite aqueous solution with continuous stirring at a temperature in the range of 0 ° c . to 5 ° c . until the diazotization is accomplished . the coupling compound afforded by the aforementioned process is added therein , and the ph value of the reaction solution is adjusted to 6 . 5 by nahco 3 with continuous stirring at a temperature in the range of 15 ° c . to 25 ° c . until the coupling reaction is accomplished . the orange product of the following formula ( 1 ) is obtained by salting - out , filtration and wash with brine water . 28 . 1 parts of 2 - sulfonic - 4 - β - sulfatoethylhydroxy - aniline are dispersed in 300 parts of ice water , and then 22 . 8 parts of 32 % hcl are added therein with thorough stirring , followed by the addition of 6 . 9 parts of sodium nitrite with continuous stirring at a temperature in the range of 0 ° c . to 5 ° c . until the diazotization is accomplished . 15 . 2 parts of 3 , 5 - diaminobenzoic acid are added to an aqueous solution ( 100 ml ) containing 22 . 8 parts of 32 % hcl with stirring for 30 minutes at a temperature in the range of 0 ° c . to 5 ° c ., followed by the addition of the diazotizing compound afforded by the aforementioned process with continuous stirring until the coupling reaction is accomplished . 56 . 2 parts of 4 - β - sulfatoethylsulfone - aniline are dispersed in 600 parts of ice water , and then 45 . 6 parts of 32 % hcl aqueous solution are added therein with thorough stirring , followed by the addition of 13 . 8 parts of sodium nitrite aqueous solution with continuous stirring at a temperature in the range of 0 ° c . to 5 ° c . until the diazotization is accomplished . the coupling compound afforded by the aforementioned process is added therein , and the ph value of the reaction solution is adjusted to 6 . 5 by nahco 3 with continuous stirring at a temperature in the range of 15 ° c . to 25 ° c . until the coupling reaction is accomplished . the orange product of the following formula ( 2 ) is obtained by salting - out , filtration and wash with brine water . according to the synthetic methods of examples 1 and 2 , the dyestuff compounds of the following examples 3 - 15 are obtained . in table 1 , the color appearance is the color of the dyestuff compound dissolved in water . 1 part of the dyestuff compound prepared in example 1 is dissolved in 100 parts of distilled water to prepare a stock solution . 20 parts of the dye solution are poured into a dyeing vessel . 4 . 8 parts of glauber &# 39 ; s salt are added to the dyeing vessel and then distilled water is poured therein to make up the total amount of the dyeing solution in the dyeing vessel to be 75 parts in total . after that , 5 parts of 320 g / l soda ash are added to the dyeing vessel . 4 parts of pre - wet woven cotton fabric are put into the dyeing solution , followed by covering and locking the dyeing vessel , and shaking the dyeing vessel to survey the dye . then , the dyeing vessel is put into a thermostatic bath , followed by switching on the rotating knob . the temperature is raised to 60 ° c . in 30 minutes and then the temperature is kept for 60 minutes for fixation . after dyeing , the dyed fabric is washed with cold water , followed by washing , dehydrating them and drying . finally , an orange fabric with good build up and good tinctorial yield is obtained . 3 parts of the dyestuff compound prepared in example 2 are dissolved in 100 ml of water to obtain a 20 parts / l padding liquor . 25 ml of alkali solvent ( taking 15 ml / l of naoh and 30 parts / l of glauber &# 39 ; s salt ) is added to the padding liquor and stirred thoroughly . the resultant solution is then put into a pad roller machine . the cotton fabric is padded by the roller pad machine , and batched for 4 hours under room temperature . the obtained orange fabric is orderly washed with cold water , boiling water for 10 minutes , boiling non - ionic detergent for 10 minutes , again with cold water and then dried to obtain an orange fabric with good build up and good tinctorial yield . 100 parts of urea , 10 parts of m - nitrobenzene sulfonic acid sodium salt , 20 parts of sodium bicarbonate , 55 parts of sodium alginate , and 815 parts of lukewarm water ( 1000 parts in total ) are stirred in a vessel to obtain a completely homogeneous printing paste . 3 parts of the dyestuff prepared in example 3 are sprayed in 100 parts of the above printing paste and stirred to make a homogeneous colored paste . an adequate size piece of twilled cotton fabric is covered with a 100 mesh 45 ′- twilled printing screen and then painted with the colored paste on the printing screen to give a colored fabric . this colored fabric is placed in an oven at 65 ° c . for 5 minutes until dry and then put into a steaming oven using saturated steam of 102 ˜ 105 ° c . for 10 minutes . the obtained orange fabric is orderly washed with cold water , boiling water for 10 minutes , boiling non - ionic detergent for 10 minutes , again with cold water and then dried to obtain an orange fabric with good build up and good tinctorial yield . from the foregoing description , the technology according to the present invention achieves the objects of the invention and conforms to the patent requirements of novelty , inventive step and industrial applicability . although the present invention has been explained in relation to its preferred examples , it is to be understood that many other possible modifications and variations can be made without departing from the scope of the invention as hereinafter claimed .