TY - JOUR
T1 - Improved Preparation of the Clathrate Host Compound Tri-o-thymotide and Related Trisalicylide Derivatives
AU - Gnaim, Jallal M.
AU - Green, Bernard S.
AU - Arad-Yellin, Rina
AU - Keehn, Philip M.
PY - 1991/7/1
Y1 - 1991/7/1
N2 - In order to improve the relatively low yield (ca. 35%) previously observed in the synthesis of tri-o-thymotide (TOT, 1) from o-thymotic acid (2), the cyclodehydration was studied using a variety of conditions. The low yield is due to the formation of di-o-thymotide (DOT, 3), previously reported, and at least three other products (4-6), which apparently result from the acid-catalyzed decarboxylation of 2 and subsequent condensation with thymol (7). Using pyridine as a solvent, side-product formation is inhibited. Under appropriate conditions, namely, neat POCl3 at 50 °C, the yield of 1 is 93%. Other salicylic acid derivatives also give high yields of the corresponding “trimers” under these conditions, thus providing a general, improved preparation of a family of potential clathrate host substances.
AB - In order to improve the relatively low yield (ca. 35%) previously observed in the synthesis of tri-o-thymotide (TOT, 1) from o-thymotic acid (2), the cyclodehydration was studied using a variety of conditions. The low yield is due to the formation of di-o-thymotide (DOT, 3), previously reported, and at least three other products (4-6), which apparently result from the acid-catalyzed decarboxylation of 2 and subsequent condensation with thymol (7). Using pyridine as a solvent, side-product formation is inhibited. Under appropriate conditions, namely, neat POCl3 at 50 °C, the yield of 1 is 93%. Other salicylic acid derivatives also give high yields of the corresponding “trimers” under these conditions, thus providing a general, improved preparation of a family of potential clathrate host substances.
UR - http://www.scopus.com/inward/record.url?scp=0040103468&partnerID=8YFLogxK
U2 - 10.1021/jo00014a037
DO - 10.1021/jo00014a037
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AN - SCOPUS:0040103468
SN - 0022-3263
VL - 56
SP - 4525
EP - 4529
JO - Journal of Organic Chemistry
JF - Journal of Organic Chemistry
IS - 14
ER -