Palladium free processes for preparation of acrylate compounds

A process for the preparation of a compound having formula (1), or a pharmaceutically acceptable salt thereof:

• wherein:
• X is halo, CN, CF3, or OH;
• R1 is (C1-C6)alkyl;
• a 5-, 6-, 7-, 8-, 9-, or 10-membered aryl or heteroaryl;
• or a 3-, 4-, 5-, 6-, 7-, 8-, 9-, or 10-membered cycloalkyl or heterocycloalkyl group;
• wherein the heteroaryl or heterocycloalkyl group can have from 1 to 3 heteroatoms independently selected from O, N or S;
• or a carbon atom in the cycloalkyl or heterocycloalkyl group can be part of a C═O group;
• R2 is selected from (C1-C6) alkyl or benzyl;
• comprising:
• (a) contacting a compound of formula (2):
• wherein said R1 and R2 are as defined above in compound (1);
• with an acid HA in a solvent-1, and in the presence of a nitrous salt;
• (b) introducing a halogenating agent, a cyanating agent, a trifluoromethylation agent, or a hydroxylating agent, optionally in the presence of a solvent-2, to form said compound (1);
• wherein said solvent-1 and solvent-2 can be identical or different;
• and
• Wherein said compound (2) is prepared in a process free of palladium catalyst.