Select * from MyTab where Brief = 'русские буквы'

Unclosed quote before the characterstring '='.
Incorrect syntax near '='.

Select * from MyTab where Brief = '123'
Select * from MyTab where Brief = 'asdfdgfgfgfg'

[NT]
        locale = enu, us_english, cp1251
        locale = fra, french, iso_1
        locale = deu, german, iso_1
        locale = rus, russian, cp1251
        locale = hun, us_english, cp1250
        locale = ell, us_english, cp1253
        locale = heb, us_english, cp1255
        locale = ara, us_english, cp1256
        locale = trk, us_english, cp1254
        locale = esp, spanish, iso_1
        locale = jpn, japanese, sjis
        locale = japanese, japanese, sjis
        locale = chs, chinese, eucgb
        locale = cht, tchinese, big5
        ; locale = kor, korean, eucksc
        locale = us_english.utf8, us_english, utf8
        locale = default, us_english, cp1251 

declare @q varchar(20)
select @q = 'русские буквы'
Select * from MyTab where Brief = @q