Multicomponent synthesis of 4-arylidene-2-phenyl-5(4H)-oxazolones (azlactones) using a mechanochemical approach

BMC Chemistry

Table 1 Physical data of the synthesized Azlactones 2a-i

No	Ar	m.p. (°C) found/reported	Yield (%) G.^a/Conv.^b	Time (min) G.^a/Conv.^b	(YE) G./Conv.
2a	C₆H₅	166–168/169 [40]	90/72	4/120	22.6/0.6
2b	4-MeOC₆H₄	155–156/154 [28]	93/70	5/120	18.6/0.58
2c	4-ClC₆H₄	189–190/190 [28]	96/69	10/120	9.6/0.57
2d	4-Me₂NC₆H₄	205–206/208 [28]	91/69	12/120	7.6/0.57
2e	4-NO₂C₆H₄	238–240/241 [28]	96/68	10/120	9.6/0.56
2f	2-ClC₆H₄	150–152/153 [28]	88/72	12/120	7.3/0.6
2g	2-BrC₆H₄	144–145/144 [27]	87/68	13/120	6.7/0.56
2h	3,4-(OMe)₂C₆H₃	148–150/152 [27, 40]	87/70	8/120	9.7/0.58
2i	–CH=CHC₆H₅	130–131/131 [40]	79/71	6/120	13.2/0.59

G grinding, Conv conventional, YE yield economy
^aGeneral conditions for the mechanochemical procedure: glycine (1.0 mmol) aromatic aldehyde (1.0 mmol), benzoyl chloride (1.0 mmol), fused sodium acetate (1.0 mmol) and acetic anhydride (cat.) were grinded in a mortar and pestle at room temperature for 4–13 min
^bGeneral conditions for the conventional procedure: N-benzoyl glycine (1.2 mmol), aromatic aldehyde (1.0 mmol), acetic anhydride (3.0 mmol) and fused sodium acetate (1.5 mmol) on a hot plate to liquefaction, followed by heating on a water path for 2 h

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