Table 3. Reaction Optimization Using K₃PO₄ Base Equivalents^a.

entry	base	equiv	temperature (°C)	time (h)	oxazoline yield (%)b3a	oxazole yield (%)b4a
1	K3PO4	0.3	60	12	70	0
2	K3PO4	0.5	60	12	85	0
3	K3PO4	1.0	60	12	90	0
4	K3PO4	1.5	60	12	65	30
5	K3PO4	1	MWc, 60	0.13	94	0

^aReaction was performed using 1a (1.18 mmol) and 2a (1.18 mmol).

^bYield of the isolated product.

^cMicrowave reactions were carried out in a microwave model no. CATA R (Catalyst Systems, Pune) using a power of 280 W.