CROSS APPLY VALUES[/url] was made for this;

;WITH Mysample (Record_id, Col1, Col2, Col3, Col4, Col5) AS (

SELECT 101, 'A', 'A', 'B', 'A', 'A' UNION ALL

SELECT 102, 'B', 'B', NULL, NULL, 'B' UNION ALL

SELECT 103, 'C', 'C', 'C', NULL, 'C' UNION ALL

SELECT 104, 'D', 'C', 'D', 'D', 'D'

)

SELECT Record_id, Newcol

FROM Mysample

CROSS APPLY (

SELECT Newcol = CASE WHEN MAX(Newcol) = MIN(Newcol) THEN MAX(Newcol) ELSE NULL END

FROM (VALUES (Col1), (Col2), (Col3), (Col4), (Col5)) X (Newcol)

) d

WHERE Newcol IS NOT NULL