Near the bottom of this paper on COVID-19 drugs and vaccines https://pubs.acs.org/doi/10.1021/acscentsci.0c00272
I found the patent relevant to the Moderna vaccine listed as W02017070626: https://patents.google.com/patent/WO2017070626A2/en?oq=WO2017070626
And a general formula: Formula IA):
or a salt or isomer thereof, wherein 1 is selected from 1, 2, 3, 4, and 5; m is selected from 5, 6, 7, 8, and 9; Mi is a bond or M’ ; R4 is unsubstituted Ci_3 alkyl, or -(CH2)nQ, in which Q is OH, -NHC(S)N®2, -NHC(0)N®2, -N®C(0)R, -N®S(0)2R, -N®R8, -NHC(=NR9)N®2, -NHC(=CHR9)N®2, -OC(0)N®2, -N®C(0)OR, heteroaryl or heterocycloalkyl; M and M’ are independently selected
from -C(0)0-, -OC(O)-, -C(0)N(R’)-, -P(0)(OR’)0-, -S-S-, an aryl group, and a heteroaryl group; and R2 and R3 are independently selected from the group consisting of H, CM4 alkyl, and C2-i4 alkenyl.