Thanks to Martin Weiss, Tirthankar Chakravarty and Nick Cox for their
replies. I used the solution from  Tirthankar Chakravarty with local
instead og global and it worked.
 /* begin */
 sysuse auto, clear
 local M_1 "gear_ratio displacement turn"
 local M_2 "length weight trunk"
 local M_3 "headroom rep78 mpg"
 forv i=1/3 {
        logit foreign `M_`i''
        estimates store logit_M_`i' , title(M_`i')
 }
 /* end */
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