TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The microwave applicator is designed as a cavity resonator of reflection-type. The reaction tube is axially aligned to a central symmetry axis of the waveguide. The cavity resonator is operated in E01n-mode, where n is 1-200. A standing wave is formed in the cavity resonator.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: The irradiation of the reaction mixture with microwave is carried out in an extensive microwave transparent reaction tube within a microwave generator connected with a hollow conductor over a waveguide. The irradiation of the reaction mixture is carried out in a cavity resonator with coaxial transition of the microwave. The reaction product is heated by the microwave irradiation at 120-500 degrees C. The microwave irradiation is carried out at a pressure, which is above the atmospheric pressure. Preferred Components: (I) is an ester of an aromatic carboxylic acid with 1-4C monoalcohol. The amine compound is primary or secondary amine. Preferred Definitions:    Either R1, R2 = 2-24C aliphatic residue, 6-12C aryl or 5-12 ring membered heteroaromatic group (all optionally substituted), (-(R7O)m-R8) or (-(R9-N(R10))r-(R10)); or    NR1R2 = a ring having 4 or more ring members;    R3 = optionally substituted, cyclic, through-conjugated system with (4a+2) pi -electron, and further carries at least one ester group (-COOR4);    R4 = 2-24C hydrocarbon and further carries one or more further hydroxyl groups;    R7 = 2-6C alkylene;    R8 = H, 1-24C hydrocarbon or -R7-NR11R12; either    R11, R12 = 1-24C aliphatic, 5-12 ring membered (hetero)aryl or poly(oxyalkylene) group with 1-50 poly(oxyalkylene) units in which the poly(oxyalkylene) units are derived from 2-6C alkylene oxide units; or    NR11R12 = ring having 4-6 or more members;    R9 = 2-6C alkylene;    R10 = H, up to 24C (hydroxy)alkyl, polyoxyalkylene of formula -(R7-O)p-R8 or polyiminoalkylene of formula -(R9-N(10))q-(R10);    a = 1-5;    m = 2-50;    p, q = 1-50; and    r = 1-20.    ACTIVITY - Insect Repellent.    MECHANISM OF ACTION - None given.    EXAMPLE - m-Toluic acid butyl ester (2.4 kg) was added into an autoclave followed by the addition of diethylamine (3.66 kg) and sodium ethylate (100 g) as catalyst and homogenized under stirring. The obtained reaction mixture (5 l/hour) was continuously pumped at an operating pressure of 35 bar and exposed to a microwave power of 2.8 kW, where 90% of reaction product was absorbed. The residence time of the reaction mixture in the irradiating zone was 34 seconds. The reaction mixture had a temperature of 305 degrees C at the end of the reaction tube. The reaction mixture was directly cooled to room temperature after leaving the reactor, where 76% of the conversion was carried out. The reaction mixture was worked up to give m-toluic acid diethylamide (1.8 kg and 98% purity).