VIRAL INHIBITORS, THE SYNTHESIS THEREOF, AND INTERMEDIATES THERETO

1 . A method of treating a patient with post-transplant cytomegalovirus (CMV) infection and/or disease comprising orally administering maribavir or a pharmaceutically acceptable salt thereof to the patient in an amount of 400 mg twice a day, wherein maribavir is administered as a pharmaceutical composition comprising:

(i) maribavir:

or a pharmaceutically acceptable salt thereof, and

(ii) one or more of the following:

or a pharmaceutically acceptable salt thereof,

or a pharmaceutically acceptable salt thereof; or

or a pharmaceutically accept salt thereof.

2 . The method of claim 1 , wherein the patient is a transplant recipient.

3 . The method of claim 2 , wherein the patient has undergone a hematopoietic stem cell transplant (HSCT) or solid organ transplant (SOT).

4 . The method of claim 1 , wherein the CMV infection and/or disease is refractory to treatment with ganciclovir, valganciclovir, cidofovir or foscarnet.

5 . The method of claim 1 , wherein the CMV infection and/or disease is intolerant to treatment with ganciclovir, valganciclovir, cidofovir or foscarnet.

6 . The method of claim 1 , wherein the pharmaceutical composition comprises less than 0.1% w/w of Compound 2 or a salt thereof relative to maribavir (e.g., as measured by HPLC), less than 0.1% w/w of Compound 3 or a salt thereof relative to maribavir (e.g., as measured by HPLC), and/or less than 0.1% w/w of Compound 4 or a salt thereof relative to maribavir (e.g., as measured by HPLC).

7 . The method of claim 1 , wherein maribavir is Form VI having a PSD of d(50) less than about 400 μm.

8 .- 11 . (canceled)

12 . A method of preparing maribavir polymorph Form VI, wherein the method comprises crystallizing maribavir Form VI from a crystallization mixture comprising maribavir, or a pharmaceutically acceptable salt thereof, and isopropyl acetate.

13 . The method of claim 12 , wherein the crystallization mixture comprises less than 0.2% w/w of water (e.g., as measured by 1 H NMR or Karl Fischer).

14 . The method of claim 13 , wherein the crystallization mixture comprises less than 0.09% w/w of water (e.g., as measured by 1 H NMR or Karl Fischer).

15 . The method of claim 12 , wherein the crystallization mixture comprises between about 17-20% w/w of maribavir, or a pharmaceutically acceptable salt thereof (e.g., as measured by 1 H NMR).

16 . The method of claim 15 , wherein the crystallization mixture comprises between about 17-19% w/w of maribavir, or a pharmaceutically acceptable salt thereof (e.g., as measured by 1 H NMR).

17 . The method of claim 12 , wherein a seed crystal is added to the crystallization mixture.

18 . The method of claim 17 , the seed crystal is maribavir, or a pharmaceutically acceptable salt thereof.

19 . The method of claim 12 , comprising a step of reacting compound 3 or a salt thereof, under suitable reaction conditions to provide maribavir, or a pharmaceutically acceptable salt thereof, wherein the seed crystal is added in an amount of between about 0.05% and 0.30% w/w relative to compound 3, or a salt thereof.

20 . The method of claim 19 , wherein the seed crystal is added in an amount of about 0.15% w/w relative to compound 3, or a salt thereof.

21 . The method of claim 17 , wherein the size of the seed crystal (d(50)) is between about 2.25-7.00 μm.

22 . The method of claim 21 , wherein the size of the seed crystal (d(50)) is between about 2.75-6.25 μm.

23 . A method of preparing maribavir or a salt thereof, comprising a step of

(a) reacting compound 5:

or a salt thereof,

with compounds 6 and 7:

under suitable reaction conditions to provide compound 2, or a salt thereof.

24 . A method of preparing maribavir:

or a pharmaceutically acceptable salt thereof, comprising a step of:

(a) reacting compound 3:

or a salt thereof,

under suitable reaction conditions to provide maribavir, or a pharmaceutically acceptable salt thereof,

wherein compound 3, or a salt thereof, is prepared by a method comprising a step of

a) reacting compound 2:

or a salt thereof,

under suitable reaction conditions to provide compound 3, or a pharmaceutically acceptable salt thereof,

wherein compound 2, or a salt thereof, is prepared by a method comprising a step of

(a) reacting compound 5:

or a salt thereof,

with compounds 6 and 7:

under suitable reaction conditions to provide compound 2, or a salt thereof.