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Part-IIImpact of Microwave…RNHNNH 2ON +OYR 1CamphorsulfonicAcidMWI, 80 o C,15 minROOYR 1CH(OMe) 2MWI, 82 o C,15 minNH 2 XHNH 2OR 1YNRX36R = CH 3 , i-Pr, i-Bu etcR 1 = CH 2 Ph, C 2 H 5 , allyl, i-Pr, CH 3 , Ph etcY = O, NH, N, NC 2 H 5X = NPh, NCONH 2 , O etcMicrowave-assisted solid-phase Diels-Alder cycloaddition reactions of 2(1H)-pyrazinones with dienophiles to yield the products of general structure 37, have beendiscussed by Kaval et al. 40 All steps in the solid-phase protocol (linking, cycloaddition,cleavage) were carried out under controlled microwave irradiation conditions. In general,significant rate enhancements were found along with the reduction of reaction times fromhours or days to minutes.ClHNNN OON O Dimethyl acetylenedicarboxylate (DMAD),1,2 dichlorbenzeneCs 2 CO 3 , ResinMWI, 70 o C,MWI, 220 o C,R 1 5 min Cl N R 1 20-40 min H 3 COOC R 1R 1 = Ph, OCH 3TFA-DCMMWI, 120 o C,10-40 minCOOCH 3HNOH 3 COOC R 1COOCH 337291