Study On The Synthesis Technology Of 1-(4-Methoxyphenyl)Thiourea

1-(4-methoxyphenyl)thioureais an important dye intermediate andit is the main raw material for the synthesis of dyes like 2-amino-6-methoxy-benzothiazole and 3-methyl-6-methoxy-benzothiazole hydrazine. The paperwas effectively prepared for 1-(4-methoxyphenyl)thiourea from 4 -nitroanisole by reduction and compounded with ammonium thiocyanate and we studied theirbetter synthesis conditions.This paper mainly carried out in two partsofresearch work.The first part mainly studied on the better parameters for the synthesis of p-anisidine.In this experiment,sodium sulfide solution is reducing agent. We obtained the better synthesis parameters of p-anisidine:4-nitroanisole4g, molor ratio of 4-nitroanisole and Sodiumsulfidel:1.8,ethano110mL,Sodium sulfide solution’s mass fraction 15%,sodium sulfide solution dropwise over 50min,the totalladder heating reaction time 4.5h, the temperature respectively 90℃,2h; 100℃,1h; 110℃,1.5h.The yield of product was 69.6%.The second part mainly studied on the better parameters for the synthesis of 1-(4-methoxyphenyl)thiourea. 1-(4-methoxyphenyl)thiourea was effectively prepared from p-anisidine and ammonium thiocyanate and acidic catalyst.The optimum conditions were p-anisidine 5.7g, ammonium thiocyanat 3.1g, hydrochloric acid 3.3ml, water 8ml, reaction temperature 90℃, reaction time 9 h.The results oflarger scale experiments proved that the average yield was 95%and purity of the product was 99.3%.In this method, The writer choosed acid as catalyst and water as solvent. It avoided the use of organic solvents and CS2. Compared to the conv-entional method,the process of the synthesis technology was facile, safe, environmental-lyand the product yield was high.