Kinetic and Mechanistic Investigation of Pyrano[2,3-d]pyrimidine Formation in the Presence of Catalyst under Novel One-Pot Three-Component Reaction

Table 2

Rate constants 𝑘_obs (min⁻¹ M⁻¹), 𝑘₁=𝑘_ove (min⁻¹ M⁻²) for the reaction between 2 (10⁻² M), 3 (10⁻² M), and 1 (10⁻² M) in the presence of sodium acetate (as a catalyst) and both solvents methanol (32.6)^a and a mixture of ethanol and water (ethanol : water, 1 : 1), (52.12)^d.

Solvent: methanol (32.6)^a
𝑇 (°C)	𝑇= 20°C	𝑇= 25°C	𝑇= 30°C	𝑇= 35°C	𝑇= 40°C	𝑇= 45°C	𝑇= 50°C
𝑘obs	3.5092	6.2492	9.0095	11.7607	14.50	18.15	22.10
	(0.0011)^b	(0.0094)	(0.0102)	(0.0065)	(0.0189)	(0.0099)	(0.0199)
𝑘^cove	350.92	624.92	900.95	1176.07	1450	1815	2210
Solvent: mix ethanol/water (52.12)^d
𝑇 (°C)	𝑇= 20°C	𝑇= 25°C	𝑇= 30°C	𝑇= 35°C	𝑇= 40°C	𝑇= 45°C	𝑇= 50°C
𝑘obs	9.4693	12.6398	14.9811	17.7596	20.507	24.609	29.705
	(0.007)^b	(0.0093)	(0.0116)	(0.0139)	(0.0164)	(0.0186)	(0.0193)
𝑘ove	946.93	1263.98	1498.11	1775.96	2050.7	2460.9	2970.5

a,dDielectric constant.
bSD (standard deviation).
^cIs overall rate constant.