Dimethoxytrityl

{{Chembox

|ImageFile = dimethoxytrityl.svg

|ImageSize = 120px

|IUPACName = bis(4-methoxyphenyl)-phenylmethyl radical

|OtherNames = {{Unbulleted list

|4,4'-Benzylidenedianisole

|4,4'-Dimethoxytrityl cation

|4,4'-Dimethoxytriphenylmethyl radical

|Bis(p-methoxyphenyl)phenylmethyl radical

|DMT

}}

|Section1 = {{Chembox Identifiers

| index_label = -H

| index1_label = +

| CASNo = 7500-76-7

| ChemSpiderID = 74017

| ChemSpiderID1 = 9080474

| EC_number = 231-356-7

| UNII = FAN78ASF8G

| PubChem1 = 10905215

| PubChem = 82012

| SMILES = COC1=CC=C(C=C1)C(C2=CC=CC=C2)C3=CC=C(C=C3)OC

| InChI = InChI=1S/C21H20O2/c1-22-19-12-8-17(9-13-19)21(16-6-4-3-5-7-16)18-10-14-20(23-2)15-11-18/h3-15,21H,1-2H3

| InChIKey = RIRAVPPUGSNYOU-UHFFFAOYSA-N

| InChI1=1S/C21H19O2/c1-22-19-12-8-17(9-13-19)21(16-6-4-3-5-7-16)18-10-14-20(23-2)15-11-18/h3-15H,1-2H3/q+1

| InChIKey1 = JLRBVXBVFZQEHA-UHFFFAOYSA-N

| SMILES1 = COC1=CC=C(C=C1)C(=C2C=CC(=[O+]C)C=C2)C3=CC=CC=C3

}}

|Section2 = {{Chembox Properties

|MolarMass = 303.4

|Formula = C21H19O2

}}

}}

Dimethoxytrityl, often abbreviated DMT, is a protecting group widely used for protection of the 5'-hydroxy group in nucleosides, particularly in oligonucleotide synthesis.{{cite journal |url=https://www.tandfonline.com/doi/abs/10.1080/07328319908044664 |title=Dimethoxytrityl Removal in Organic Medium: Efficient Oligonucleotide Synthesis Without Chlorinated Solvents |journal=Nucleosides and Nucleotides |pages=1207–1209 |doi=10.1080/07328319908044664 |date=1999 |first1=Achim |last1=Krotz |first2=Douglas |last2=Cole |first3=Vasulinga |last3=Ravikumar|volume=18 |issue=6–7 |url-access=subscription }}

It is usually bound to a molecule, but can exist as a stable cation in solution, where it appears bright orange.{{cite web |url=https://scienceblogs.com/moleculeoftheday/2006/09/05/dimethoxytrityldmt-orange-you |title=Dimethoxytrityl/DMT (Orange you glad you protected that alcohol?) |website=Molecule of the Day |date=2006-09-05 |access-date=2022-05-03}}