We observed that the reaction of 6,8-dibromo-2-methyl-3,l-benzoxazin-4-one, 5, with primary amines occurs very slowly in ethanol solution at room temperature and that the product is usually the corresponding 2-acetamido-3,5-dibromobenzamide, 6. These results are in sharp contrast to the results reported for the corresponding reactions with 6-bromo-2-methyl-3,l-benzoxazin-4-one, 5'. The latter occur very rapidly to give the corresponding N-(2-carboxy-4-bromophenyl)-N-substituted-acetamidine intermediate, 4, which undergoes cyclodehydration in solution (sometimes spontaneously) to give the corresponding N-substituted-2-methyl-6-bromoquinazolin-4-ones, V. It was inferred from these observations that the qualititive difference in chemistry exhibited by 5 and 5' is somehow attributable to the presence of the substituent in the 8-position of compound 5.
This paper aims to present a Lord-Shulman theory of one relaxation time and the dual-phase-lag model of two-relaxation times to study the effect of gravity on both the micro-elongated thermoelasticity layer and the elastic layer in the above. The normal mode analysis was used to obtain the expressions of the displacement components, the micro-elongational scalar, and the stress components. Comparisons between the physical quantities were getting numerically and epitomized graphically. The results depict the effect of the presence and absence of gravity and the relaxation times on all the physical quantities.
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