And eight) or N,N-dimethylthiocarbamoyl chloride (Table 1, entries six and 9). It is actually worth

And eight) or N,N-dimethylthiocarbamoyl chloride (Table 1, entries six and 9). It is actually worth noting that the bulky carbamoyl chlorides (i.e., N,N-diethylcarbamoyl chloride and N,N-dimethylthiocarbamoyl chloride) considerably lower the conversion prices when compared with N,N-dimethylcarbamoyl chloride below the exact same set of carbamoylation conditions (Table 1).Molecules 2021, 26, 6421 PEER Assessment Molecules 2021, 26, x FOR44of 16 ofScheme two. Carbamoylation of five,7,20-O-trimethylsilybin. Scheme two. Carbamoylation of 5,7,20-O-trimethylsilybin.Table 1. Reaction conditions and yields for the carbamoylation of five,7,20-O-trimethylsilybin (three). Along with getting the important 3-O-carbamoyl-5,7,20-O-trimethylsilybin (5) inEntry 1 two 3 four five six 7 8Entry 1 two 3 4 5 six 7 879 yield, a little amount of Reaction Circumstances Dicarbamoyl3-Carbamoyl5,7,20-O-trimethyl-3,23-O-di-(N,N-dimethylcarbamoyl)silybin (four) was also isolated in SM a a a item item Et3 N DMAP DCM Temp. Time 13 yield (Table 1, entry 1). Adding extra triethyl amine and DMAP, prolonging reaction Me2 NCOCl (4 eq) 4time, or eqincreasing reaction temperature can slightly increase the (13 ) eq 1 0.1 M r.t. 16 h three (0 ) 5 (79 ) four yields for Et2 NCOCl (four eq) 4 eq 1 eq 0.1 M r.t. 16 h three (50 ) six (34 ) 7 (9 ) Me2 NCSCl (four eq) 43,23-O-dicarbamoylsilbybin (4), but h eq 1 eq 0.1 M r.t. 16 cannot3promote the completion of carbamoylation at (59 ) eight (25 ) 9 (7 ) Me2 NCOCl (4 eq) 4the primary alcoholic hydroxyl group at C-23 (Table 1, entries four and 7). This Nitrocefin Data Sheet regioseleceq 1 eq 0.1 M 50 C 16 h three (0 ) 5 (73 ) four (23 ) Et2 NCOCl (4 eq) four eq 1 eq 0.1 M 50 C 16 h 3 (29 ) 6 (46 ) 7 (19 ) tive carbamoylation in the secondary alcoholic hydroxyl 8 (42 ) at C-3 might be(14 ) group extended to Me2 NCSCl (four eq) four eq 1 eq 0.1 M 50 C 16 h three (40 ) 9 C other carbamoyl Mchlorides. A 16 related three (0 ) tendency was observed when reacting Me2 NCOCl (six eq) six eq three eq 0.2 50 h 5 (58 ) four (38 ) Et2 NCOC (six eq) 65,7,20-O-trimethylsilybin (three) with16 h eq 3 eq 0.two M 50 C 3 (0 ) (69 ) (24 ) N,N-diethylcarbamoyl6chloride (Table 1, 7entries 5 and Me2 NCSCl (6 eq) six eq three eq 0.2 M 50 C 16 h 3 (7 ) 8 (58 ) 9 (25 ) eight) or N,N-dimethylthiocarbamoyl chloride (Table 1, entries six and 9). It can be worth noting a Isolated that the bulky carbamoylyields. chlorides (i.e., N,N-diethylcarbamoyl chloride and N,N-dimethylthiocarbamoyl chloride) substantially lower the conversion rates when two.two. Structure FAUC 365 MedChemExpress Determination of 3-O-Carbamoyl-5,7,20-O-trimethylsilybin 5 compared with N,N-dimethylcarbamoyl chloride below the identical set of carbamoylation The structure of situations (Table 1). five,7,20-O-trimethyl-3-O-(N,N-dimethylcarbamoyl)-silybin (five) was elucidated by interpreting its 1D- and 2D-NMR information (Table 2), too as high resolution MS and IR data. The structure of five was characterized by the existence Table 1. Reaction circumstances and yields for the carbamoylation of five,7,20-O-trimethylsilybin (three).of a single signal at two.85 ppm representing 6 protons in its 1 H NMR spectrum (Supplementary Components) and Reaction Situations Dicarbamoyl3-Carbamoyl13 at (Thio)carbamoyl Chloride 36.75 (36.08) and 155.28 in its C NMR spectrum aan further dimethylcarbamoyl SM for item a product a Et3N DMAP DCM Temp. Time group when compared with the starting material five,7,20-O-trimethylsilybin (3), which was three (0 ) 5 (79 ) four (13 ) Me2NCOCl (four eq) four eq 1 eq 0.1 M r.t. 16 h The three (50 ) six (34 ) 7 to 3-OH Et2NCOCl (four eq) corroborated by the HRMS information. r.t. dimethylcarbamoyl group in 5 w.