Did merck patent methyldopa in 1962?

Short answer: Yes. Merck (Merck & Co., the US/Merck Sharp & Dohme) developed methyldopa and were the patent assignee for early protections around its manufacture and use in the early 1960s, with Aldomet entering the market shortly after FDA approval in the early 1960s (around 1961–1962).

If you want the exact patent numbers and links (e.g., the primary compound patent and any process/formulation patents), I can look them up in USPTO/Google Patents or Espacenet. Do you want US patents, European patents, or both?