He received a medical degree from the University of Santo Domingo in 1952. Upon graduation Sánchez moved to New York City to specialize in gastroenterology at New York University while working as a resident in the Bronx.
However, he quickly became absorbed with painting, his new-found hobby. Initially self-taught, his talent developed rapidly. In 1956, Sanchez enrolled at the National Academy of Fine Arts in New York City, where he received instruction from French and American artists, including Robert Philip and René Bouché. Sánchez's technique, magnificent color sense, and whimsical style received immediate critical acclaim at exhibitions in New York City; Havana; and Santo Domingo; and later in Paris; Washington, D.C.; and Mexico City.
By 1959, Sánchez decided to leave medicine and focus on his artwork. That year, he embarked on a world tour which brought him international recognition. During his tour, he exhibited in Tokyo, Hong Kong, New Delhi, Tel Aviv, Athens, Rome and at the Royal Academy in London. In 1960, he won a Gold Medal Award at the Biennial in São Paulo, Brazil.
In 1964, the Dominican Republic appointed Sánchez cultural attaché of the Dominican Republic Embassy in Tokyo.
In 1966, became the first Dominican painter to exhibit at the Association Fraternal Latinoamericano. He later exhibited at Galleria 88 in Rome; the Federal Reserve in Washington, D.C.; and galleries in New York City, including the Caravan Gallery, Hammer Gallery, and in 1975 at the Bodley Gallery, which featured the premier surrealist artists including Max Ernst, Yves Tanguy and René Magritte.
In 1966, Sánchez moved to Miami, where he also became a breeder of champion Shih Tzu and Japanese Chin dogs with his long-time partner, Gilbert Stanley Kahn, son of philanthropist Janet Annenberg Hooker and nephew of publisher and diplomat Walter Annenberg.
Sánchez died in Miami of colon and lung cancer, age 61. He was survived by Kahn and a sister.