“…Synthesis of aryl and 3‐thiophenyl diazo esters (2 a – i and k) : All aryl diazo acetates were prepared by reported procedure [10] . Aryl acetates (1 equiv., 5 mmol) were dissolved in acetonitrile (10 ml) in a clean oven dried round bottom flask, added DBU (1,8‐Diazabicyclo[5.4.0]undec‐7‐ene) (1.2 equiv., 6 mmol), stirred for 10 minutes, p‐ABSA (4‐Acetamidobenzenesulfonyl azide) (1.2 equiv., 6 mmol) was added, stirred for 4 hours in dark and r.t; after completion acetonitrile was removed under vacuum, diluted with ethyl acetate (25 ml), washed with water and organic layer was dried with brine and sodium sulphate, purified with flash column chromatography in silica gel (60–120 mesh size) with 5% ethyl acetate in hexane to yield 98% [10b] …”