(+)-CSA Catalyzed Multicomponent Synthesis of 1-[(1,3-Thiazol-2-ylamino)methyl]-2-naphthols and Their Ring-Closure Reaction under Ultrasonic Irradiation

Table 4

Synthesis of naphthoxazines (2a–f) (see Scheme 4).

Product	R	Time (min)	Yield (%)
2a	Phenyl	120	53
2b	4-Bromophenyl	120	36
2c	4-Isopropylphenyl	120	69
2d	Thiophen-2-yl	120	64
2e	5-Methylfuran-2-yl	120	65
2f	5-Bromofuran-2-yl	120	57

Isolated yield.